In vitro bioactivity and drug release kinetics studies of mesoporous silica-biopolymer composites (original) (raw)

Silica-Polymer Composites as the Novel Antibiotic Delivery Systems for Bone Tissue Infection

Pharmaceutics, 2019

Bone tissue inflammation, osteomyelitis, is commonly caused by bacterial invasion and requires prolonged antibiotic therapy for weeks or months. Thus, the aim of this study was to develop novel silica-polymer local bone antibiotic delivery systems characterized by a sustained release of ciprofloxacin (CIP) which remain active against Staphylococcus aureus for a few weeks, and do not have a toxic effect towards human osteoblasts. Four formulations composed of ethylcellulose (EC), polydimethylsiloxane (PDMS), freeze-dried CIP, and CIP-adsorbed mesoporous silica materials (MCM-41-CIP) were prepared via solvent-evaporation blending method. All obtained composites were characterized in terms of molecular structure, morphological, and structural properties by using Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy (SEM/EDX), and X-ray diffraction (XRD), thermal stability by thermogravimetric analysis (TGA) and d...

Formulation and In Vitro Characterization of Bioactive Mesoporous Silica with Doxorubicin and Metronidazole Intended for Bone Treatment and Regeneration

AAPS PharmSciTech

The purpose of this study was to evaluate the surface mineralization activity and in vitro drug behavior potential of two forms of mesoporous silica: powder and granulate. Ordered mesoporous SiO 2 powder was synthesized by surfactant-assisted sol-gel process using tetraethoxysilane as a silica precursor and hexadecyltrimethylammonium bromide as the structure-directing agent. The granulate was prepared using silica powder and ethyl cellulose as a binding agent. Metronidazole (MT)-an anti-inflammatory substance and doxorubicin hydrochloride (ChD)-an anti-cancer drug were chosen as drug models for delivery studies. The results of structural characteristic studies, utilizing transmission electron microscope (TEM) and scanning electron microscope (SEM) images, powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption (BET) measurements, show that obtained materials have two-dimensional hexagonal p6mm symmetry, high specific surface area, narrow pore size, and a satisfactory mineralization behavior in the simulated body solution (SBF, pH = 7.4). The release rate of drugs depends upon the structural features of the drug molecules and the form of the carrier material. Of both the drugs analyzed, faster release was observed for small MT molecules characterized by weaker interactions with the carrier. In addition, the slower drug release was observed with granulate form due to increased diffusion barrier for drugs. Obtained results prove that the MT/ChD-loaded silica formulations could be attractive materials for filling bone defects and for local delivery systems.

An in situ synthesis of mesoporous SBA-16/hydroxyapatite for ciprofloxacin release: in vitro stability and cytocompatibility studies

Journal of materials science. Materials in medicine, 2014

The present work developed a biomaterial (HA/SBA-16) based on the growth of calcium phosphate (HA) particles within an organized silica structure (SBA-16) to evaluate its application as a drug delivery system. The samples were charged with ciprofloxacin as a model drug and in vitro release assays were carried out. The samples were characterized by elemental analysis (CHN), Fourier transform infrared spectroscopy, nitrogen adsorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), small angle X-ray scattering (SAXS) and X-ray diffraction. The results obtained by TEM, SEM and SAXS reveal a well-defined cubic arrangement of a uniform spherical mesoporous structure, an intrinsic characteristic of these materials, which indicated that SBA-16 and HA/SBA-16 could potentially encapsulate bioactive molecules by means of ordered mesopores. It was found that both surface interaction and pore volume affect the rate and amount of ciprofloxacin released from the mesop...

Mesoporous Silica-Bioglass Composite Pellets as Bone Drug Delivery System with Mineralization Potential

International Journal of Molecular Sciences, 2021

For decades, local bone drug delivery systems have been investigated in terms of their application in regenerative medicine. Among them, inorganic polymers based on amorphous silica have been widely explored. In this work, we combined two types of amorphous silica: bioglass and doxycycline-loaded mesoporous silica MCM-41 into the form of spherical granules (pellets) as a bifunctional bone drug delivery system. Both types of silica were obtained in a sol-gel method. The drug adsorption onto the MCM-41 was performed via adsorption from concentrated doxycycline hydrochloride solution. Pellets were obtained on a laboratory scale using the wet granulation-extrusion-spheronization method and investigated in terms of physical properties, drug release, antimicrobial activity against Staphylococcus aureus, mineralization properties in simulated body fluid, and cytotoxicity towards human osteoblasts. The obtained pellets were characterized by satisfactory mechanical properties which eliminate...

Mesoporous silica nanoparticles in target drug delivery system: A review

International Journal of Pharmaceutical Investigation, 2015

Due to lack of specifi cation and solubility of drug molecules, patients have to take high doses of the drug to achieve the desired therapeutic effects for the treatment of diseases. To solve these problems, there are various drug carriers present in the pharmaceuticals, which can used to deliver therapeutic agents to the target site in the body. Mesoporous silica materials become known as a promising candidate that can overcome above problems and produce effects in a controllable and sustainable manner. In particular, mesoporous silica nanoparticles (MSNs) are widely used as a delivery reagent because silica possesses favorable chemical properties, thermal stability, and biocompatibility. The unique mesoporous structure of silica facilitates effective loading of drugs and their subsequent controlled release of the target site. The properties of mesoporous, including pore size, high drug loading, and porosity as well as the surface properties, can be altered depending on additives used to prepare MSNs. Active surface enables functionalization to changed surface properties and link therapeutic molecules. They are used as widely in the fi eld of diagnosis, target drug delivery, bio-sensing, cellular uptake, etc., in the bio-medical fi eld. This review aims to present the state of knowledge of silica containing mesoporous nanoparticles and specifi c application in various biomedical fi elds.

Synthesis and surface modification of mesoporous silica nanoparticles and its application as carriers for sustained drug delivery

Drug Delivery, 2014

High drug loading is one of the important issues in the drug delivery research, especially the drug delivery system by oral administration. If high drug loading carriers are utilized the times of drug intake could be significantly reduced. Accordingly in this study, ordered mesoporous SBA-15 modified with (3-aminopropyl) triethoxysilane (APTES) was used as a carrier for nonsteroidal anti-inflammatory drug and optimization of the loading process was done. SBA-15 silica material with rope-like morphology was synthesized and modified by post-synthesis method with APTES. The synthesized SBA-15 and modified SBA-15 were characterized by XRD, SEM, thermal analysis and FT-IR spectroscopy. Loading optimization experiments were performed by changing the factors affecting the drug loading, such as temperature, time, stirring rate, Ibuprofen/SBA-15 ratio. The results of drug delivery experiments showed that the surface modification of SBA-15 with amino groups significantly increases the drug loading and decreases the drug delivery rate.

Mesoporous silica nanoparticle-functionalized poly(methyl methacrylate)-based bone cement for effective antibiotics delivery

Journal of Materials Science: Materials in Medicine, 2011

Poly(methyl methacrylate)-based bone cements are functionalized with mesoporous silica nanoparticles (MSN) to enable a highly efficient and sustained release of antibiotics to reduce the risk of post-operative joint infection. To overcome the limited drug release of 5% for only 1 day with the current commercial-grade bone cements, a 8 wt% MSN-formulated bone cement is able to increase the drug release efficiency by 14-fold and sustain the release for up to 80 days. The loaded MSN is suggested to build up an effective network of rod-shaped silica particles with uniformly arranged nanoporous channels, which is responsible for the effective drug diffusion and extend time-release to the external surfaces. MSN has no detrimental effect on the critical weight-bearing bending modulus and compression strength of bone cement. In vitro assay test results show a much sustained antibacterial effect and low cytotoxicity of MSN demonstrating the potential applicability of MSN-formulated bone cement.

Bioactive silica-based drug delivery systems containing doxorubicin hydrochloride: In vitro studies

Colloids and Surfaces B: Biointerfaces, 2012

This study reports the applicability of sol-gel derived silica and silica-polydimethylsiloxane (silica-PDMS) composites as a potential bioactive implantable drug delivery system for doxorubicin hydrochloride (DOX). These composites also contain calcium chloride (CaCl 2) and triethylphosphate as precursors of Ca 2+ and (PO 4) 3− ions. These composites were immersed for 20 days in a simulated body fluid (SBF) at 37 • C to study the release rate of the DOX, dissolution of the silica and the formation of hydroxyapatite on the composites' surface. The results show that the release rate of the DOX can be effectively tailored by either the addition of a polydimethylsiloxane (PDMS), or by varying the amount of CaCl 2 , where the elution rate of DOX increases with increasing amount of the CaCl 2 precursor. Importantly, irrespective of the amount of CaCl 2 , no burst release of DOX has been observed in any of the silica-PDMS system investigated. On the other hand, a slow release of DOX has been observed with a trend that followed a zero (0)-order kinetics for a total of 20 days of elusion. The dissolution of silica in SBF was ca. two-times faster than that of silica-PDMS, with the former reaching an average saturation level of 80 g/mL whilst the latter reached 46 g/mL within 20 days. Both the silica and the silica-PDMS composites show bioactivity i.e. they absorb calcium phosphate from SBF. Within 10 days, a tenfold increase in the concentration of calcium phosphate deposit has been observed on the silica-PDMS relative to the silica. The constant rates of DOX release observed for the silica-PDMS composites indicate that the calcium phosphate deposit do not obstruct controlled release of the drug.

Hierarchical mesoporous bio-polymer/silica composites co-templated by trimethyl chitosan and a surfactant for controlled drug delivery

MedChemComm, 2011

In this communication, we report the facile synthesis of hierarchical mesoporous bio-polymer/silica composite materials with bimodal mesopores using a dual-template of the cationic N,N,N-trimethyl chitosan (TMCs) and the anionic sodium dodecyl sulfate (SDS) via one-step synthetic strategy. Tetraethoxysilane (TEOS) was used as a silica source. The nitrogen adsorption/desorption measurements and transmission electron microscopy analysis showed the hierarchical structure of the mesoporous bio-polymer/silica composites with bimodal mesopores having an average pore size of 5-7 nm with the visible voids between the silica nanoparticles, which allow the mesoporous bio-polymer/ silica composites to encapsulate a large number of guest drug molecules, Ibuprofen (IBU) or 5fluorouracil (5-FU), due to their high surface area and pore volume. In addition, the mesoporous chitosan-silica composites also had a long term biocompatibility for the target release of the drug molecules to the CEM cells, MCF cells, etc. as well as a pH sensitive controlled release behavior of the drug molecules.