Malathi Mathiyazhakan | Nanyang Technological University (original) (raw)

Papers by Malathi Mathiyazhakan

Indian Journal of Medical Research, 2022

Asian Pacific Journal of Health Sciences

Background: A nationwide lockdown in response to the ongoing coronavirus disease 2019 pandemic ha... more Background: A nationwide lockdown in response to the ongoing coronavirus disease 2019 pandemic has disrupted various health surveys. Limited movements due to restricted public-transports, and the need to maintain social-distancing, make data collection at the field site through conventional methods such as face-to-face interviews challenging. Objectives: The objective of the study was to overcome such issues, we document a complete online survey, using mobile technologies, for public health research, and deployable during disasters. Methods: The survey form was uploaded online, and for the 1st time in India, the participant information page, consent, and assent forms were also deployed online. Informed consent forms from participants were captured electronically as hand-drawn signatures. A structured, electronic-questionnaire was shared to the participants’ smartphones, and the collected data were stored in a server using Research Electronic Data Capture, real-time. Results: Within ...

Current HIV Research

Introduction: Analysis of local risks at sub-national levels and tailored interventions are being... more Introduction: Analysis of local risks at sub-national levels and tailored interventions are being emphasized for effective HIV management. Andhra Pradesh (AP) is a high HIV prevalence state in India, with the second-highest number of people with HIV (PWH) and a consistent decline in HIV prevalence at the state level. Probing further into the region and district-wise levels and trends of HIV prevalence will provide critical insights into sub-regional epidemic patterns. Hence, this paper analyzes the regional and district-level trends of HIV prevalence among pregnant women attending the antenatal clinics (ANC) from 2003 to 2019 in AP, South India. Methods: HIV prevalence data collected from pregnant women in AP during HIV sentinel surveillance (HSS) between 2003 and 2019 was used for trend analysis. The consistent sites were grouped into three regions (Coastal Andhra, Rayalaseema and Uttar Andhra), totaling 39 sites, including 21 rural and 18 urban sites. Regional and district-level H...

International Journal Of Community Medicine And Public Health, 2022

Background: The SARS-CoV-2 virus with the emergence of new highly transmissible variants at spora... more Background: The SARS-CoV-2 virus with the emergence of new highly transmissible variants at sporadic intervals has bought unparallel damage to global health not only by its direct effect on mortality but also through its impact on lifestyle diseases. This study aimed to understand the lifestyle changes that have occurred among people across India during the period of nationwide lockdown.Methods: The present cross-sectional study was conducted among a large cross-section of people across India (n=1559) with mHealth technology using research electronic data capture (Redcap) platform. The online tool was pre-tested and validated and was disseminated through an easily accessible online social media platform. The online survey form was incorporated with a participant information sheet, an informed consent/assent form with an electronic signature capture method.Results: Among the 1559 participants, 292 (18.72%) were of age less than 25 years, 724 (46.4%) were of age between 25 to 39 years...

Background: Spatial and risk-related heterogeneity among high-risk HIV populations marks the prev... more Background: Spatial and risk-related heterogeneity among high-risk HIV populations marks the prevalence, dynamics, and management of HIV. Identifying the spatial heterogeneity of disease prevalence and risk heterogeneity at a specific location is crucial for fine-tuning the strategic interventions. On this background, we analysed the behavioural data and HIV prevalence of IDUs, in a state-specific manner. Objectives: To structure the IDU population based on their risk of infection and location, and to determine the HIV prevalence for each of the IDU subpopulation based on their spatial distribution and risk profile. Methods: We analysed the behavioural data and HIV prevalence obtained from the National Integrated Biological and Behavioural Surveillance (IBBS), a nationwide cross-sectional community-based study conducted in 2014-2015. We included the data obtained from 19,902 IDUs across 53 domains in 29 states of India for analysis. We grouped the IDUs into different categories, bas...

Indian Journal of Community Medicine : Official Publication of Indian Association of Preventive & Social Medicine, 2021

Background: The HIV sentinel surveillance (HSS) serves to estimate the levels and trend of HIV pr... more Background: The HIV sentinel surveillance (HSS) serves to estimate the levels and trend of HIV prevalence among high-risk, bridge, and general population and monitors HIV management at national, state, and district levels. Data from HSS are valuable in understanding the risk factors associated with HIV transmission with particular demographic characteristics. Objectives: The objective was to analyze the sociodemographic profile of the pregnant mothers attending the antenatal care (ANC) clinics in Karnataka, in order to understand the dynamics of HIV within the general population in Karnataka. Materials and Methods: Study design: this was a cross-sectional study conducted using consecutive sampling method. Study setting: the surveillance was conducted at select antenatal clinics, in Karnataka, India, between January and March, in the years 2013, 2015, and 2017. Methodology: in total, 74,278 eligible pregnant women aged between 15 and 49 years, attending the sentinel sites for the fir...

Background: The human immunodeficiency virus (HIV) epidemic in India is generally considered to b... more Background: The human immunodeficiency virus (HIV) epidemic in India is generally considered to be more concentrated, with the focus on high-risk groups including female sex workers (FSWs). The Integrated Biological and Behavioral Surveillance (IBBS), the first nationwide surveillance conducted during 2014-2015, collected many key indicators, including indicators related to HIV/STI transmission. The purpose of this study was to develop an index score for each domain surveyed and to identify focus areas for interventions among FSWs. Methods: The study population consisted of 27,007 FSWs. Forty high-risk related covariates of HIV/STI transmission, demographic characteristics, sexual history, condom practices, knowledge of HIV/STI and biological variables were considered. The original data set was examined using the correlation matrix and was reduced to 15 highly-correlated factors using principal component analysis. The factors were further improved using varimax rotation and the perc...

International Journal of Maternal and Child Health and AIDS (IJMA)

Background and Objective: Periodic tracking of the trends and the levels of HIV prevalence at reg... more Background and Objective: Periodic tracking of the trends and the levels of HIV prevalence at regional and district levels helps to strengthen a state’s HIV/AIDS response. HIV prevalence among pregnant women is crucial for the HIV prevalence estimation of the general population. Karnataka is one of the high HIV prevalence states in India. Probing regional and district levels and trends of HIV prevalence provides critical insights into district-level epidemic patterns. This paper analyzes the region- and district-wise levels and trends of HIV prevalence among pregnant women attending the antenatal clinics (ANC) from 2003 to 2019 in Karnataka, South India. Methods: HIV prevalence data collected from pregnant women in Karnataka during HIV Sentinel Surveillance (HSS) between 2003 and 2019 was used for trend analysis. The consistent sites were grouped into four zones (Bangalore, Belgaum, Gulbarga and Mysore regions), totaling 60 sites, including 30 urban and 30 rural sites. Regional and ...

Medicine

HIV prevalence is higher among Men who have Sex with Men (MSM), owing to their unsafe sexual beha... more HIV prevalence is higher among Men who have Sex with Men (MSM), owing to their unsafe sexual behavior. Further, MSM indulge in behaviors such as consumption of alcohol/oral drugs and/or injecting during/before sex that poses the risk of unsafe behaviors, thereby increasing their vulnerability to HIV. The study aims to analyze the factors associated with HIV infection among the multi-risk MSM using any substances with those MSM who do not use substances. Community-based cross-sectional survey design using probability-based sampling between October 2014 and November 2015. For the nation-wide Integrated Biological and Behavioral Surveillance (IBBS), 23,081 MSM were recruited from 4067 hotspots in 108 districts across India. Information on demographics, sexual behaviors, substance use, sexual partners, and awareness on HIV and its management was collected from the consented respondents using computer-assisted personal interview (CAPI) by trained personnel. Blood samples were tested for HIV. Statistical analyses were done, to study the associations between substance use and its influence on high-risk sexual behaviors and HIV infection. One in 3 MSM (33.88%) in India were substance users, thus exhibiting “multi-risk” (MR) behaviors. Significantly higher HIV prevalence (3.8%, P< .05) was reported amongMR-MSM, despite 97.2% of them being aware of HIV. Higher HIV prevalence among MSM exhibiting homosexual behavior for 1 year is of specific concern, as this accounts to recent infections and indicates the increased vulnerability of the infection among the new entrants. Substance-use resulting in high-risk sexual behavior was significantly associated with higher HIV prevalence among MR-MSM. Integrated targeted interventions focusing on safe sex and safe-IDU practices among MR-MSM are required to end the disease transmission. Abbreviations: AIDS = Acquired Immuno Deficiency Syndrome, BS = Bi-sexual, CAPI = Computer Assisted Personal Interview, DBS = Dried Blood Spot, FSW = Female Sex Worker, HIV = Human Immunodeficiency Virus, HRG = High-Risk Group, IBBS = Integrated Biological and Behavioral Surveillance, IDU = Injecting Drug User, MR-MSM = Men who have Sex with Men exhibiting Multi-Risk behavior, MSM =Men who have Sex with Men, NACO = National AIDS Control Organization, PLHIV = People Living with HIV, SACS = State AIDS Control Society, STI = Sexually Transmitted Infection, TG= Transgender, TI = Targeted Interventions, UARI = Unprotected anal receptive intercourse.

International Journal of Maternal and Child Health and AIDS (IJMA)

Background and Objectives: The purpose of this study was to analyze trends in HIV prevalence and ... more Background and Objectives: The purpose of this study was to analyze trends in HIV prevalence and risk factors associated with HIV infection among pregnant women attending antenatal clinics in Odisha State, India. Methods: Data were from the HIV Sentinel Surveillance (HSS) among pregnant women, a descriptive cross-sectional study using consecutive sampling method and conducted in India. Data and samples were collected from pregnant women attending select antenatal clinics that act as designated sentinel sites in Odisha State, India, during the three months surveillance period and in three surveillance years: 2013, 2015, and 2017. All eligible pregnant women aged between 15 and 49 years, attending the sentinel sites for the first time during the surveillance period, were included. Information on their socio-demographic characteristics and blood samples were also collected. Results: In total, 38,384 eligible pregnant women were included in the survey. Of these, 107 women were HIV posit...

Nano-Micro Letters

• Photo-responsive liposomes are powerful carriers for topical and transdermal drug delivery to s... more • Photo-responsive liposomes are powerful carriers for topical and transdermal drug delivery to superficial tissues like skin, eyes, and mucous membranes. • Photo-responsive liposomes can be built with gold nanoparticles, which allow the use of near-infrared lights as the light source for deep tissue penetration and low phototoxicity. • This review summarizes the latest development and scientific understanding of this complex in delivering drugs for tuning cell signaling pathway and treating cancer.

Science China Materials, 2016

This report describes the design and synthesis of gold nanostars (AuNSs) containing liposomes by ... more This report describes the design and synthesis of gold nanostars (AuNSs) containing liposomes by the in situ reduction of gold precursor, HAuCl4 (pre-encapsulated within the liposomes) through HEPES diffusion and reduction. Compared with the conventional process that encapsulates the pre-synthesized gold nanoparticles into liposomes during the thin-film hydration step, this facile and convenient method allows the formation and simultaneous encapsulation of AuNSs within liposomes. The absorption spectra of AuNSs can be tuned between visible and near infra-red (NIR) regions by controlling the size and morphology of AuNSs through varying the concentrations of HAuCl4 and HEPES. As a proof of concept, we demonstrate the synthesis of AuNSs with a maximum absorbance at 803 nm within the temperature-sensitive liposomes. These liposomes can produce stronger photoacoustic signals (1.5 fold) in the NIR region than blood. Furthermore, when there are drugs (i.e., doxorubicin) within these liposomes, the irradiation with the NIR pulse laser will disrupt the liposomes and trigger the 100% release of these pre-encapsulated drugs within 10 seconds. In comparison, there is neglectable contrast enhancement or minor release (10%) of drugs for the pure liposomes under the same conditions. Finally, cell experiment shows the potential therapeutic application of this system.

Journal of Biomedical Optics, 2016

Photoacoustic imaging has become an emerging tool for theranostic applications. Not only does it ... more Photoacoustic imaging has become an emerging tool for theranostic applications. Not only does it help in in vivo, noninvasive imaging of biological structures at depths but it can also be used for drug release and therapeutic applications. We explore near-infrared light-sensitive liposomes coated with gold nanostars (AuNSs) for both imaging and drug release applications using a photoacoustic imaging system. Being amphiphilic, the liposomes lipid bilayer and the aqueous core enable encapsulation of both hydrophobic and hydrophilic drugs. The AuNSs on the surface of the liposomes act as photon absorbers due to their intrinsic surface plasmon resonance. Upon excitation by laser light at specific wavelength, AuNSs facilitate rapid release of the contents encapsulated in the liposomes due to local heating and pressure wave formation (photoacoustic wave). Herein, we describe the design and optimization of the AuNSs-coated liposomes and demonstrate the release of both hydrophobic and hydrophilic model drugs (paclitaxel and calcein, respectively) through laser excitation at nearinfrared wavelength. The use of AuNSs-coated liposomes as contrast agents for photoacoustic imaging is also explored with tissue phantom experiments. In comparison to blood, the AuNSs-coated liposomes have better contrast (approximately two times) at 2-cm imaging depth.

Bioengineering & Translational Medicine, 2016

Near-infrared (NIR) light-responsive liposomes are attractive carriers for targeted and controlle... more Near-infrared (NIR) light-responsive liposomes are attractive carriers for targeted and controlled drug delivery to the superficial organ or tissue (e.g., skin). This work describes the development of NIR-responsive liposomes by incorporating gold nanostars within liposomes composed of Phospholipon 90 g and cholesterol. Following cellular delivery, photothermal effect around the gold nanostar upon NIR stimulation induces microcavitation and liposome phase transition which consequently triggers the release of encapsulated molecules. Taking GFP plasmid as an example, we demonstrate enhanced gene transfection into fibroblasts following NIR treatment.

Journal of visualized experiments : JoVE, 2016

Photo-responsive nanoparticles (NPs) have received considerable attention because of their potent... more Photo-responsive nanoparticles (NPs) have received considerable attention because of their potential in providing spatial, temporal, and dosage control over the drug release. However, most of the relevant technologies are still in the development process and are unprocurable by clinics. Here, we describe a facile fabrication of these photo-responsive NPs with commercially available gold NPs and thermo-responsive liposomes. Calcein is used as a model drug to evaluate the encapsulation efficiency and the release kinetic profile upon heat/light stimulation. Finally, we show that this photo-triggered release is due to the membrane disruption caused by microbubble cavitation, which can be measured with hydrophone.

Colloids and surfaces. B, Biointerfaces, Jan 22, 2014

Drug-carriers, capable of releasing the drug at the target sites upon external stimuli, are attra... more Drug-carriers, capable of releasing the drug at the target sites upon external stimuli, are attractive for theranostic applications. In recent years, photo-responsive nanoparticles (NPs) have received considerable attention because of their potentials in providing spatial, temporal, and dosage control over the drug release. However, most of the relevant technologies are still in the process of development and are unprocurable by the clinics. Here, we demonstrated facile fabrication of these photo-responsive NPs by loading hydrophilic gold NPs within thermo-responsive liposomes. Calcein was used as a model drug to evaluate the encapsulation efficiency and the release kinetic profile upon heat/light stimulation. Furthermore, we characterized their size, morphology, phase transition temperature and stability. Finally, we demonstrated that this photo-triggered release might be due to the membrane disruption caused by microbubble cavitation.

Drug Development Research, 2006

ABSTRACT

Indian Journal of Medical Research, 2022

Asian Pacific Journal of Health Sciences

Background: A nationwide lockdown in response to the ongoing coronavirus disease 2019 pandemic ha... more Background: A nationwide lockdown in response to the ongoing coronavirus disease 2019 pandemic has disrupted various health surveys. Limited movements due to restricted public-transports, and the need to maintain social-distancing, make data collection at the field site through conventional methods such as face-to-face interviews challenging. Objectives: The objective of the study was to overcome such issues, we document a complete online survey, using mobile technologies, for public health research, and deployable during disasters. Methods: The survey form was uploaded online, and for the 1st time in India, the participant information page, consent, and assent forms were also deployed online. Informed consent forms from participants were captured electronically as hand-drawn signatures. A structured, electronic-questionnaire was shared to the participants’ smartphones, and the collected data were stored in a server using Research Electronic Data Capture, real-time. Results: Within ...

Current HIV Research

Introduction: Analysis of local risks at sub-national levels and tailored interventions are being... more Introduction: Analysis of local risks at sub-national levels and tailored interventions are being emphasized for effective HIV management. Andhra Pradesh (AP) is a high HIV prevalence state in India, with the second-highest number of people with HIV (PWH) and a consistent decline in HIV prevalence at the state level. Probing further into the region and district-wise levels and trends of HIV prevalence will provide critical insights into sub-regional epidemic patterns. Hence, this paper analyzes the regional and district-level trends of HIV prevalence among pregnant women attending the antenatal clinics (ANC) from 2003 to 2019 in AP, South India. Methods: HIV prevalence data collected from pregnant women in AP during HIV sentinel surveillance (HSS) between 2003 and 2019 was used for trend analysis. The consistent sites were grouped into three regions (Coastal Andhra, Rayalaseema and Uttar Andhra), totaling 39 sites, including 21 rural and 18 urban sites. Regional and district-level H...

International Journal Of Community Medicine And Public Health, 2022

Background: The SARS-CoV-2 virus with the emergence of new highly transmissible variants at spora... more Background: The SARS-CoV-2 virus with the emergence of new highly transmissible variants at sporadic intervals has bought unparallel damage to global health not only by its direct effect on mortality but also through its impact on lifestyle diseases. This study aimed to understand the lifestyle changes that have occurred among people across India during the period of nationwide lockdown.Methods: The present cross-sectional study was conducted among a large cross-section of people across India (n=1559) with mHealth technology using research electronic data capture (Redcap) platform. The online tool was pre-tested and validated and was disseminated through an easily accessible online social media platform. The online survey form was incorporated with a participant information sheet, an informed consent/assent form with an electronic signature capture method.Results: Among the 1559 participants, 292 (18.72%) were of age less than 25 years, 724 (46.4%) were of age between 25 to 39 years...

Background: Spatial and risk-related heterogeneity among high-risk HIV populations marks the prev... more Background: Spatial and risk-related heterogeneity among high-risk HIV populations marks the prevalence, dynamics, and management of HIV. Identifying the spatial heterogeneity of disease prevalence and risk heterogeneity at a specific location is crucial for fine-tuning the strategic interventions. On this background, we analysed the behavioural data and HIV prevalence of IDUs, in a state-specific manner. Objectives: To structure the IDU population based on their risk of infection and location, and to determine the HIV prevalence for each of the IDU subpopulation based on their spatial distribution and risk profile. Methods: We analysed the behavioural data and HIV prevalence obtained from the National Integrated Biological and Behavioural Surveillance (IBBS), a nationwide cross-sectional community-based study conducted in 2014-2015. We included the data obtained from 19,902 IDUs across 53 domains in 29 states of India for analysis. We grouped the IDUs into different categories, bas...

Indian Journal of Community Medicine : Official Publication of Indian Association of Preventive & Social Medicine, 2021

Background: The HIV sentinel surveillance (HSS) serves to estimate the levels and trend of HIV pr... more Background: The HIV sentinel surveillance (HSS) serves to estimate the levels and trend of HIV prevalence among high-risk, bridge, and general population and monitors HIV management at national, state, and district levels. Data from HSS are valuable in understanding the risk factors associated with HIV transmission with particular demographic characteristics. Objectives: The objective was to analyze the sociodemographic profile of the pregnant mothers attending the antenatal care (ANC) clinics in Karnataka, in order to understand the dynamics of HIV within the general population in Karnataka. Materials and Methods: Study design: this was a cross-sectional study conducted using consecutive sampling method. Study setting: the surveillance was conducted at select antenatal clinics, in Karnataka, India, between January and March, in the years 2013, 2015, and 2017. Methodology: in total, 74,278 eligible pregnant women aged between 15 and 49 years, attending the sentinel sites for the fir...

Background: The human immunodeficiency virus (HIV) epidemic in India is generally considered to b... more Background: The human immunodeficiency virus (HIV) epidemic in India is generally considered to be more concentrated, with the focus on high-risk groups including female sex workers (FSWs). The Integrated Biological and Behavioral Surveillance (IBBS), the first nationwide surveillance conducted during 2014-2015, collected many key indicators, including indicators related to HIV/STI transmission. The purpose of this study was to develop an index score for each domain surveyed and to identify focus areas for interventions among FSWs. Methods: The study population consisted of 27,007 FSWs. Forty high-risk related covariates of HIV/STI transmission, demographic characteristics, sexual history, condom practices, knowledge of HIV/STI and biological variables were considered. The original data set was examined using the correlation matrix and was reduced to 15 highly-correlated factors using principal component analysis. The factors were further improved using varimax rotation and the perc...

International Journal of Maternal and Child Health and AIDS (IJMA)

Background and Objective: Periodic tracking of the trends and the levels of HIV prevalence at reg... more Background and Objective: Periodic tracking of the trends and the levels of HIV prevalence at regional and district levels helps to strengthen a state’s HIV/AIDS response. HIV prevalence among pregnant women is crucial for the HIV prevalence estimation of the general population. Karnataka is one of the high HIV prevalence states in India. Probing regional and district levels and trends of HIV prevalence provides critical insights into district-level epidemic patterns. This paper analyzes the region- and district-wise levels and trends of HIV prevalence among pregnant women attending the antenatal clinics (ANC) from 2003 to 2019 in Karnataka, South India. Methods: HIV prevalence data collected from pregnant women in Karnataka during HIV Sentinel Surveillance (HSS) between 2003 and 2019 was used for trend analysis. The consistent sites were grouped into four zones (Bangalore, Belgaum, Gulbarga and Mysore regions), totaling 60 sites, including 30 urban and 30 rural sites. Regional and ...

Medicine

HIV prevalence is higher among Men who have Sex with Men (MSM), owing to their unsafe sexual beha... more HIV prevalence is higher among Men who have Sex with Men (MSM), owing to their unsafe sexual behavior. Further, MSM indulge in behaviors such as consumption of alcohol/oral drugs and/or injecting during/before sex that poses the risk of unsafe behaviors, thereby increasing their vulnerability to HIV. The study aims to analyze the factors associated with HIV infection among the multi-risk MSM using any substances with those MSM who do not use substances. Community-based cross-sectional survey design using probability-based sampling between October 2014 and November 2015. For the nation-wide Integrated Biological and Behavioral Surveillance (IBBS), 23,081 MSM were recruited from 4067 hotspots in 108 districts across India. Information on demographics, sexual behaviors, substance use, sexual partners, and awareness on HIV and its management was collected from the consented respondents using computer-assisted personal interview (CAPI) by trained personnel. Blood samples were tested for HIV. Statistical analyses were done, to study the associations between substance use and its influence on high-risk sexual behaviors and HIV infection. One in 3 MSM (33.88%) in India were substance users, thus exhibiting “multi-risk” (MR) behaviors. Significantly higher HIV prevalence (3.8%, P< .05) was reported amongMR-MSM, despite 97.2% of them being aware of HIV. Higher HIV prevalence among MSM exhibiting homosexual behavior for 1 year is of specific concern, as this accounts to recent infections and indicates the increased vulnerability of the infection among the new entrants. Substance-use resulting in high-risk sexual behavior was significantly associated with higher HIV prevalence among MR-MSM. Integrated targeted interventions focusing on safe sex and safe-IDU practices among MR-MSM are required to end the disease transmission. Abbreviations: AIDS = Acquired Immuno Deficiency Syndrome, BS = Bi-sexual, CAPI = Computer Assisted Personal Interview, DBS = Dried Blood Spot, FSW = Female Sex Worker, HIV = Human Immunodeficiency Virus, HRG = High-Risk Group, IBBS = Integrated Biological and Behavioral Surveillance, IDU = Injecting Drug User, MR-MSM = Men who have Sex with Men exhibiting Multi-Risk behavior, MSM =Men who have Sex with Men, NACO = National AIDS Control Organization, PLHIV = People Living with HIV, SACS = State AIDS Control Society, STI = Sexually Transmitted Infection, TG= Transgender, TI = Targeted Interventions, UARI = Unprotected anal receptive intercourse.

International Journal of Maternal and Child Health and AIDS (IJMA)

Background and Objectives: The purpose of this study was to analyze trends in HIV prevalence and ... more Background and Objectives: The purpose of this study was to analyze trends in HIV prevalence and risk factors associated with HIV infection among pregnant women attending antenatal clinics in Odisha State, India. Methods: Data were from the HIV Sentinel Surveillance (HSS) among pregnant women, a descriptive cross-sectional study using consecutive sampling method and conducted in India. Data and samples were collected from pregnant women attending select antenatal clinics that act as designated sentinel sites in Odisha State, India, during the three months surveillance period and in three surveillance years: 2013, 2015, and 2017. All eligible pregnant women aged between 15 and 49 years, attending the sentinel sites for the first time during the surveillance period, were included. Information on their socio-demographic characteristics and blood samples were also collected. Results: In total, 38,384 eligible pregnant women were included in the survey. Of these, 107 women were HIV posit...

Nano-Micro Letters

• Photo-responsive liposomes are powerful carriers for topical and transdermal drug delivery to s... more • Photo-responsive liposomes are powerful carriers for topical and transdermal drug delivery to superficial tissues like skin, eyes, and mucous membranes. • Photo-responsive liposomes can be built with gold nanoparticles, which allow the use of near-infrared lights as the light source for deep tissue penetration and low phototoxicity. • This review summarizes the latest development and scientific understanding of this complex in delivering drugs for tuning cell signaling pathway and treating cancer.

Science China Materials, 2016

This report describes the design and synthesis of gold nanostars (AuNSs) containing liposomes by ... more This report describes the design and synthesis of gold nanostars (AuNSs) containing liposomes by the in situ reduction of gold precursor, HAuCl4 (pre-encapsulated within the liposomes) through HEPES diffusion and reduction. Compared with the conventional process that encapsulates the pre-synthesized gold nanoparticles into liposomes during the thin-film hydration step, this facile and convenient method allows the formation and simultaneous encapsulation of AuNSs within liposomes. The absorption spectra of AuNSs can be tuned between visible and near infra-red (NIR) regions by controlling the size and morphology of AuNSs through varying the concentrations of HAuCl4 and HEPES. As a proof of concept, we demonstrate the synthesis of AuNSs with a maximum absorbance at 803 nm within the temperature-sensitive liposomes. These liposomes can produce stronger photoacoustic signals (1.5 fold) in the NIR region than blood. Furthermore, when there are drugs (i.e., doxorubicin) within these liposomes, the irradiation with the NIR pulse laser will disrupt the liposomes and trigger the 100% release of these pre-encapsulated drugs within 10 seconds. In comparison, there is neglectable contrast enhancement or minor release (10%) of drugs for the pure liposomes under the same conditions. Finally, cell experiment shows the potential therapeutic application of this system.

Journal of Biomedical Optics, 2016

Photoacoustic imaging has become an emerging tool for theranostic applications. Not only does it ... more Photoacoustic imaging has become an emerging tool for theranostic applications. Not only does it help in in vivo, noninvasive imaging of biological structures at depths but it can also be used for drug release and therapeutic applications. We explore near-infrared light-sensitive liposomes coated with gold nanostars (AuNSs) for both imaging and drug release applications using a photoacoustic imaging system. Being amphiphilic, the liposomes lipid bilayer and the aqueous core enable encapsulation of both hydrophobic and hydrophilic drugs. The AuNSs on the surface of the liposomes act as photon absorbers due to their intrinsic surface plasmon resonance. Upon excitation by laser light at specific wavelength, AuNSs facilitate rapid release of the contents encapsulated in the liposomes due to local heating and pressure wave formation (photoacoustic wave). Herein, we describe the design and optimization of the AuNSs-coated liposomes and demonstrate the release of both hydrophobic and hydrophilic model drugs (paclitaxel and calcein, respectively) through laser excitation at nearinfrared wavelength. The use of AuNSs-coated liposomes as contrast agents for photoacoustic imaging is also explored with tissue phantom experiments. In comparison to blood, the AuNSs-coated liposomes have better contrast (approximately two times) at 2-cm imaging depth.

Bioengineering & Translational Medicine, 2016

Near-infrared (NIR) light-responsive liposomes are attractive carriers for targeted and controlle... more Near-infrared (NIR) light-responsive liposomes are attractive carriers for targeted and controlled drug delivery to the superficial organ or tissue (e.g., skin). This work describes the development of NIR-responsive liposomes by incorporating gold nanostars within liposomes composed of Phospholipon 90 g and cholesterol. Following cellular delivery, photothermal effect around the gold nanostar upon NIR stimulation induces microcavitation and liposome phase transition which consequently triggers the release of encapsulated molecules. Taking GFP plasmid as an example, we demonstrate enhanced gene transfection into fibroblasts following NIR treatment.

Journal of visualized experiments : JoVE, 2016

Photo-responsive nanoparticles (NPs) have received considerable attention because of their potent... more Photo-responsive nanoparticles (NPs) have received considerable attention because of their potential in providing spatial, temporal, and dosage control over the drug release. However, most of the relevant technologies are still in the development process and are unprocurable by clinics. Here, we describe a facile fabrication of these photo-responsive NPs with commercially available gold NPs and thermo-responsive liposomes. Calcein is used as a model drug to evaluate the encapsulation efficiency and the release kinetic profile upon heat/light stimulation. Finally, we show that this photo-triggered release is due to the membrane disruption caused by microbubble cavitation, which can be measured with hydrophone.

Colloids and surfaces. B, Biointerfaces, Jan 22, 2014

Drug-carriers, capable of releasing the drug at the target sites upon external stimuli, are attra... more Drug-carriers, capable of releasing the drug at the target sites upon external stimuli, are attractive for theranostic applications. In recent years, photo-responsive nanoparticles (NPs) have received considerable attention because of their potentials in providing spatial, temporal, and dosage control over the drug release. However, most of the relevant technologies are still in the process of development and are unprocurable by the clinics. Here, we demonstrated facile fabrication of these photo-responsive NPs by loading hydrophilic gold NPs within thermo-responsive liposomes. Calcein was used as a model drug to evaluate the encapsulation efficiency and the release kinetic profile upon heat/light stimulation. Furthermore, we characterized their size, morphology, phase transition temperature and stability. Finally, we demonstrated that this photo-triggered release might be due to the membrane disruption caused by microbubble cavitation.

Drug Development Research, 2006

ABSTRACT