Melina Setiawan - Academia.edu (original) (raw)

Papers by Melina Setiawan

Research paper thumbnail of Cellular therapy of corneal epithelial defect by adipose mesenchymal stem cell-derived epithelial progenitors

Stem Cell Research & Therapy

Background Persistent epithelial defects (PED), associated with limbal stem cell deficiency (LSCD... more Background Persistent epithelial defects (PED), associated with limbal stem cell deficiency (LSCD), require ocular surface reconstruction with a stable corneal epithelium (CE). This study investigated CE reformation using human adipose mesenchymal stem cells (ADSC), which derived epithelial progenitors via mesenchymal-epithelial transition (MET). Methods STEMPRO human ADSC were cultured with specific inhibitors antagonizing glycogen synthase kinase-3 and transforming growth factor-β signaling, followed by culture under a defined progenitor cell targeted-epithelial differentiation condition to generate epithelial-like cells (MET-Epi), which were characterized for cell viability, mesenchymal, and epithelial phenotypes using immunofluorescence and flow cytometry. Tissue-engineered (TE) MET-Epi cells on fibrin gel were transplanted to corneal surface of the rat LSCD model caused by alkali injury. Epithelial healing, corneal edema, and haze grading, CE formation were assessed by fluoresc...

Research paper thumbnail of Characterization of Human Transition Zone Reveals a Putative Progenitor-Enriched Niche of Corneal Endothelium

Cells

The corneal endothelium regulates corneal hydration to maintain the transparency of cornea. Lacki... more The corneal endothelium regulates corneal hydration to maintain the transparency of cornea. Lacking regenerative capacity, corneal endothelial cell loss due to aging and diseases can lead to corneal edema and vision loss. There is limited information on the existence of corneal endothelial progenitors. We conducted ultrastructural examinations and expression analyses on the human transition zone (TZ) at the posterior limbus of corneal periphery, to elucidate if the TZ harbored progenitor-like cells, and to reveal their niche characteristics. Within the narrow TZ (~190 μm width), the inner TZ-adjacent to the peripheral endothelium (PE)-contained cells expressing stem/progenitor markers (Sox2, Lgr5, CD34, Pitx2, telomerase). They were located on the inner TZ surface and in its underlying stroma. Lgr5 positive cells projected as multicellular clusters into the PE. Under transmission electron microscopy and serial block face-scanning electron microscopy and three-dimensional (3D) reconstruction, the terminal margin of Descemet's membrane was inserted beneath the TZ surface, with the distance akin to the inner TZ breadth. Porcine TZ cells were isolated and proliferated into a confluent monolayer and differentiated to cells expressing corneal endothelial markers (ZO1, Na + K + ATPase) on cell surface. In conclusion, we have identified a novel inner TZ containing progenitor-like cells, which could serve the regenerative potential for corneal endothelium.

Research paper thumbnail of A sintered graphene/titania material as a synthetic keratoprosthesis skirt for end-stage corneal disorders

Research paper thumbnail of Changes in aqueous oxidative stress, prostaglandins, and cytokines: Comparisons of low-energy femtosecond laser–assisted cataract surgery versus conventional phacoemulsification

Journal of Cataract & Refractive Surgery

Research paper thumbnail of Postnatal periodontal ligament as a novel adult stem cell source for regenerative corneal cell therapy

Journal of cellular and molecular medicine, 2018

Corneal opacities are a leading cause of global blindness. They are conventionally treated by the... more Corneal opacities are a leading cause of global blindness. They are conventionally treated by the transplantation of donor corneal tissue, which is, restricted by a worldwide donor material shortage and allograft rejection. Autologous adult stem cells with a potential to differentiate into corneal stromal keratocytes (CSKs) could offer a suitable choice of cells for regenerative cell therapy. Postnatal periodontal ligament (PDL) contains a population of adult stem cells, which has a similar embryological origin as CSK, that is cranial neural crest. We harvested PDL cells from young adult teeth extracted because of non-functional or orthodontic reason and differentiated them towards CSK phenotype using a two-step protocol with spheroid formation followed by growth factor and cytokine induction in a stromal environment (human amnion stroma and porcine corneal stroma). Our results showed that the PDL-differentiated CSK-like cells expressed CSK markers (CD34, ALDH3A1, keratocan, lumican...

Research paper thumbnail of Safety and Feasibility of Intrastromal Injection of Cultivated Human Corneal Stromal Keratocytes as Cell-Based Therapy for Corneal Opacities

Investigative ophthalmology & visual science, Jan 2, 2018

To evaluate the safety and feasibility of intrastromal injection of human corneal stromal keratoc... more To evaluate the safety and feasibility of intrastromal injection of human corneal stromal keratocytes (CSKs) and its therapeutic effect on a rodent early corneal opacity model. Twelve research-grade donor corneas were used in primary culture to generate quiescent CSKs and activated stromal fibroblasts (SFs). Single and repeated intrastromal injections of 2 to 4 × 104 cells to rat normal corneas (n = 52) or corneas with early opacities induced by irregular phototherapeutic keratectomy (n = 16) were performed, followed by weekly examination of corneal response under slit-lamp biomicroscopy and in vivo confocal microscopy with evaluation of haze level and stromal reflectivity, and corneal thickness using anterior segment optical coherence tomography (AS-OCT). Time-lapse tracing of Molday ION-labelled cells was conducted using Spectralis OCT and label intensity was measured. Corneas were collected at time intervals for marker expression by immunofluorescence, cell viability, and apoptos...

Research paper thumbnail of Application of a modified method for stem cell isolation from lipoaspirates in a basic lab

Medical Journal of Indonesia, 2009

... for sharing his invaluable expertise, to Boenjamin Setiawan, dr., PhD who delivered the idea ... more ... for sharing his invaluable expertise, to Boenjamin Setiawan, dr., PhD who delivered the idea of stem cell research, to the donors for donating their lipoaspirate, and the collaborated hospital staffs who have coordi-nated the material to be used in this ... Adi-pose-Derived Cells. ...

Research paper thumbnail of Immunogenicity characterization of mononucleated cells originated from umbillical cord blood

Medical Journal of Indonesia, 2010

Tujuan Sel punca yang diisolasi dari darah tali pusat diketahui merupakan populasi sel mononuklea... more Tujuan Sel punca yang diisolasi dari darah tali pusat diketahui merupakan populasi sel mononuklear yang terdapat dalam darah tali pusat. Hingga saat ini, telah banyak laporan mengenai penggunaan sel tipe ini sebagai alternatif transplantasi sel punca secara alogenik. Berdasarkan laporan beberapa hasil studi klinis, sel darah tali pusat dapat ditoleransi sekalipun pada kasus ketidakcocokan human leukocyte antigen (HLA) pada beberapa alel dengan jumlah kasus graft versus host reaction yang rendah. Penelitian ini mengkarakterisasi profil imunogenisitas sel mononuklear darah tali pusat yang diketahui banyak mengandung sel punca, melalui analisis reaksi alogenik yang ditimbulkannya dan dibandingkan dengan reaksi terhadap sel yang berasal dari darah tepi. Metode Aloreaktifitas dari darah tali pusat dianalisis dengan pemeriksaan mixed lymphocyte reaction (MLR) dilanjutkan dengan deteksi IFN-γ yang disekresikan ke dalam medium. Tipe HLA sel donor dan efektor diperiksa dengan pemeriksaan HLA berbasis PCR untuk menentukan reaktivitas alogenik. Lebih lanjut, tingkat ekspresi HLA kelas I dan II ditentukan dengan teknik flowcytometry menggunakan antibodi monoklonal terhadap kedua molekul tersebut. Hasil Dalam medium kultur MLR dengan sel darah tali pusat, ditemukan bahwa titer IFN-γ yang terdeteksi jauh lebih rendah daripada hasil MLR sel darah tepi. Hal ini menunjukan bahwa stimulasi alogenik yang ditimbulkan oleh sel darah tali pusat lebih rendah daripada darah tepi, sekaligus mengindikasikan rendahnya potensi rejeksi tipe sel tersebut. Hasil pemeriksaan tipe HLA menunjukkan bahwa hanya terdapat 1-3 kecocokan alel dari 8 alel pasangan sel yang digunakan dalam esai MLR. Lebih lanjut, ditemukan bahwa ekspresi molekul HLA kelas I pada sel darah tali pusat sangat rendah dan hanya sebagian kecil sel yang mengekspresikan HLA kelas II. Kesimpulan Studi ini mendemonstrasikan rendahnya imunogenisitas sel darah tali pusat melalui rendahnya IFN-γ yang disekresikan pada pemeriksaan MLR dan juga melalui rendahnya ekspresi molekul HLA kelas I serta lebih sedikitnya sel yang mengekspresikan HLA kelas II pada UCBMC. Hasil penelitian ini diharapkan akan menambah pemahaman mengenai pemanfaatan darah tali pusat sebagai sumber alternatif sel punca pada transplantasi alogenik.

Research paper thumbnail of Peran Molekul HLA dalam Proses Transplantasi Sel Punca

Jurnal Kedokteran Maranatha, 2010

Human Leukocyte Antigen (HLA) is the most important factor in determining the histocompatibility ... more Human Leukocyte Antigen (HLA) is the most important factor in determining the histocompatibility between the donor and the recipient in transplantation. HLA is a membrane-bound glycoprotein molecule encoded by several genes within chromosome 6 ...

Research paper thumbnail of Surface Modification of PMMA to Improve Adhesion to Corneal Substitutes in a Synthetic Core–Skirt Keratoprosthesis

ACS Applied Materials & Interfaces, 2015

Patients with advanced corneal disease do poorly with conventional corneal transplantation and re... more Patients with advanced corneal disease do poorly with conventional corneal transplantation and require a keratoprosthesis (KPro) for visual rehabilitation. The most widely used KPro is constructed using poly(methyl methacrylate) (PMMA) in the central optical core and a donor cornea as skirt material. In many cases, poor adherence between the PMMA and the soft corneal tissue is responsible for device "extrusion" and bacterial infiltration. The interfacial adhesion between the tissue and the PMMA was therefore critical to successful implantation and device longevity. In our approach, we modified the PMMA surface using oxygen plasma (plasma group); plasma followed by calcium phosphate (CaP) coating (p-CaP); dopamine followed by CaP coating (d-CaP); or plasma followed by coating with (3-aminopropyl)triethoxysilane (3-APTES). To create a synthetic KPro model, we constructed and attached 500 μm thick collagen type I hydrogel on the modified PMMA surfaces. Surface modifications produced significantly improved interfacial adhesion strength compared to untreated PMMA (p < 0.001). The p-CaP group yielded the best interfacial adhesion with the hydrogel (177 ± 27 mN/cm(2)) followed by d-CaP (168 ± 31 mN/cm(2)), 3-APTES (145 ± 12 mN/cm(2)), and plasma (119 ± 10 mN/cm(2)). Longer-term stability of the adhesion was achieved by d-CaP, which, after 14 and 28 days of incubation in phosphate buffered saline, yielded 164 ± 25 mN/cm(2) (p = 0.906 compared to adhesion at day 1) and 131 ± 20 mN/cm(2) (p = 0.053), respectively. In contrast, significant reduction of adhesion strength was observed in p-CaP group over time (p < 0.001). All surface coatings were biocompatible to human corneal stromal fibroblasts, except for the 3-APTES group, which showed no live cells at 72 h of culture. In contrast, cells on d-CaP surface showed good anchorage, evidenced by the expression of focal adhesion complex (paxillin and vinculin), and prominent filopodia protrusions. In conclusion, d-CaP can not only enhance and provide stability to the adhesion of collagen hydrogel on the PMMA surface but also promote biointegration.

Research paper thumbnail of S100A expression in normal corneal-limbal epithelial cells and ocular surface squamous cell carcinoma tissue

Molecular vision, 2011

To study the expression and cellular distribution of multiple S100A genes and proteins in normal ... more To study the expression and cellular distribution of multiple S100A genes and proteins in normal corneal-limbal epithelium and ocular surface squamous cell carcinoma (SCC) tissue. Normal corneal-limbal tissue was obtained from the Lions Eye Bank, Tampa, FL. Ocular surface SCC tissues were excised from patients undergoing surgery at Singapore National Eye Centre. S100A mRNA expression was measured by quantitative PCR. S100 protein distribution was determined by immunofluorescent staining analysis. Twelve S100 mRNAs were identified in human corneal and limbal epithelial cells. S100A2, A6, A8, A9, A10, and A11 mRNA was expressed at high level, while S100A1, A3, A4, A5, A6, A7, and A12 mRNA expression was low. The intracellular localization of S100A2, A6, A8, A9, A10 and A11 protein was determined in normal corneal-limbal and SCC tissues. S100A2 and S100A10 proteins were enriched in basal limbal epithelial cells of the normal tissue. S100A8 and S100A9 were found only at the surface of p...

Research paper thumbnail of Effectiveness of Antimicrobial Peptide Immobilization for Preventing Perioperative Cornea Implant-Associated Bacterial Infection

Antimicrobial Agents and Chemotherapy, 2014

Titanium (Ti) is a promising candidate biomaterial for an artificial corneal skirt. Antimicrobial... more Titanium (Ti) is a promising candidate biomaterial for an artificial corneal skirt. Antimicrobial peptide (AMP) immobilization may improve the bactericidal effect of the Ti substrate. In this study, we tested the bactericidal efficacy of a functionalized Ti surface in a rabbit keratitis model. A corneal stromal pocket was created by a femtosecond laser. The Ti films were then inserted into the pocket, and Staphylococcus aureus or Pseudomonas aeruginosa was inoculated into the pocket above the implant films. The corneas with Ti-AMP implants were compared with the corneas implanted with unprotected Ti by slit lamp observation and anterior segment optical coherence tomography (AS-OCT). Inflammatory responses were evaluated by bacterium counting, hematoxylin-eosin staining, and immunostaining. There was a lower incidence and a lesser extent of infection on rabbit corneas with Ti-AMP implants than on those with unprotected Ti implants. The bactericidal effect of AMP against S. aureus was comparable to that of postoperative prophylactic antibiotic treatment; hence, SESB2V AMP bound to the Ti implant provided functional activity in vivo, but its efficacy was greater against S. aureus than against P. aeruginosa. This work suggests that SESB2V AMP can be successfully functionalized in a rabbit keratitis model to prevent perioperative corneal infection.

Research paper thumbnail of Regulation of Toll-like receptor expression in human conjunctival epithelial cells

Mediators of inflammation, 2014

Previous studies showed marked decrease of multiple Toll-like receptor (TLR) expression in cornea... more Previous studies showed marked decrease of multiple Toll-like receptor (TLR) expression in corneal and conjunctival epithelial cells upon culture in vitro. The aim of this study was to identify factor(s) which regulate TLR expression. Primary human conjunctival epithelial cells and immortal conjunctival (IOBA-NHC) and corneal epithelial cell lines (HCET) were used. The effect of various cytokines, hypoxia, mechanical wounding, and airlifting culture on TLR expression was examined by quantitative PCR and western blot analysis. Ligand stimulated TLR activation was analyzed. TLR mRNA expression increased modestly when cultured monolayered cells were stimulated by TNF-α, IL-1α, IL-1β, IL-6, IL-8, IFN-γ (about 2-fold), hypoxia (2.1- to 4.8-fold selectively), and wounding (3.1- to 9.3-fold). In airlifted multilayered cells, TLR expression increased 7.8- to 25.9-fold compared to monolayered cells. Airlifted cells showed increased response to low concentrations of lipopolysaccharide (LPS) a...

Research paper thumbnail of Application of Graphene as Candidate Biomaterial for Synthetic Keratoprosthesis Skirt

Investigative Opthalmology & Visual Science, 2015

Synthetic keratoprostheses are required for visual rehabilitation in patients with end-stage corn... more Synthetic keratoprostheses are required for visual rehabilitation in patients with end-stage corneal blindness. This study aimed to assess the biocompatibility of graphene material and its potential as a novel synthetic keratoprosthesis skirt material for corneal tissue engineering. Human corneal stromal fibroblasts were cultured on material surfaces including pristine graphene film, graphene foam, pristine titanium (Ti) discs, and tissue culture plastic surface (TCPS). Cell attachment was assayed by immunostaining of paxillin and vinculin. Cell viability and proliferation were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and Click iT 5-ethynyl-2'-deoxyuridine (EdU) assays. The growth of fibroblasts on three-dimensional graphene foam was examined by scanning electron microscopy, and cytokine release was analyzed by enzyme-linked immunosorbent assay. Graphene films were implanted into rabbit corneal stromal pockets and examined by slit-lamp biomicroscopy, anterior segment optical coherence tomography, in vivo confocal microscopy, and histology. Pristine graphene demonstrated good biocompatibility with human stromal fibroblasts in terms of cell adhesion, viability, and proliferation. Cells on graphene films showed higher number than on TCPS control. Cells grown on graphene had 10% more proliferation than on Ti. The expression levels of IL-6 and IL-8 were reduced when cells were seeded on graphene foam as compared to Ti and graphene film. Implantation of graphene film into rabbit stroma (n = 6) did not show any signs of infection, neovascularization, or inflammation. Graphene displayed excellent short-term biocompatibility with corneal cells and tissue. This demonstrates that graphene can be developed as a tissue engineering material for use in cornea.

Research paper thumbnail of Cellular therapy of corneal epithelial defect by adipose mesenchymal stem cell-derived epithelial progenitors

Stem Cell Research & Therapy

Background Persistent epithelial defects (PED), associated with limbal stem cell deficiency (LSCD... more Background Persistent epithelial defects (PED), associated with limbal stem cell deficiency (LSCD), require ocular surface reconstruction with a stable corneal epithelium (CE). This study investigated CE reformation using human adipose mesenchymal stem cells (ADSC), which derived epithelial progenitors via mesenchymal-epithelial transition (MET). Methods STEMPRO human ADSC were cultured with specific inhibitors antagonizing glycogen synthase kinase-3 and transforming growth factor-β signaling, followed by culture under a defined progenitor cell targeted-epithelial differentiation condition to generate epithelial-like cells (MET-Epi), which were characterized for cell viability, mesenchymal, and epithelial phenotypes using immunofluorescence and flow cytometry. Tissue-engineered (TE) MET-Epi cells on fibrin gel were transplanted to corneal surface of the rat LSCD model caused by alkali injury. Epithelial healing, corneal edema, and haze grading, CE formation were assessed by fluoresc...

Research paper thumbnail of Characterization of Human Transition Zone Reveals a Putative Progenitor-Enriched Niche of Corneal Endothelium

Cells

The corneal endothelium regulates corneal hydration to maintain the transparency of cornea. Lacki... more The corneal endothelium regulates corneal hydration to maintain the transparency of cornea. Lacking regenerative capacity, corneal endothelial cell loss due to aging and diseases can lead to corneal edema and vision loss. There is limited information on the existence of corneal endothelial progenitors. We conducted ultrastructural examinations and expression analyses on the human transition zone (TZ) at the posterior limbus of corneal periphery, to elucidate if the TZ harbored progenitor-like cells, and to reveal their niche characteristics. Within the narrow TZ (~190 μm width), the inner TZ-adjacent to the peripheral endothelium (PE)-contained cells expressing stem/progenitor markers (Sox2, Lgr5, CD34, Pitx2, telomerase). They were located on the inner TZ surface and in its underlying stroma. Lgr5 positive cells projected as multicellular clusters into the PE. Under transmission electron microscopy and serial block face-scanning electron microscopy and three-dimensional (3D) reconstruction, the terminal margin of Descemet's membrane was inserted beneath the TZ surface, with the distance akin to the inner TZ breadth. Porcine TZ cells were isolated and proliferated into a confluent monolayer and differentiated to cells expressing corneal endothelial markers (ZO1, Na + K + ATPase) on cell surface. In conclusion, we have identified a novel inner TZ containing progenitor-like cells, which could serve the regenerative potential for corneal endothelium.

Research paper thumbnail of A sintered graphene/titania material as a synthetic keratoprosthesis skirt for end-stage corneal disorders

Research paper thumbnail of Changes in aqueous oxidative stress, prostaglandins, and cytokines: Comparisons of low-energy femtosecond laser–assisted cataract surgery versus conventional phacoemulsification

Journal of Cataract & Refractive Surgery

Research paper thumbnail of Postnatal periodontal ligament as a novel adult stem cell source for regenerative corneal cell therapy

Journal of cellular and molecular medicine, 2018

Corneal opacities are a leading cause of global blindness. They are conventionally treated by the... more Corneal opacities are a leading cause of global blindness. They are conventionally treated by the transplantation of donor corneal tissue, which is, restricted by a worldwide donor material shortage and allograft rejection. Autologous adult stem cells with a potential to differentiate into corneal stromal keratocytes (CSKs) could offer a suitable choice of cells for regenerative cell therapy. Postnatal periodontal ligament (PDL) contains a population of adult stem cells, which has a similar embryological origin as CSK, that is cranial neural crest. We harvested PDL cells from young adult teeth extracted because of non-functional or orthodontic reason and differentiated them towards CSK phenotype using a two-step protocol with spheroid formation followed by growth factor and cytokine induction in a stromal environment (human amnion stroma and porcine corneal stroma). Our results showed that the PDL-differentiated CSK-like cells expressed CSK markers (CD34, ALDH3A1, keratocan, lumican...

Research paper thumbnail of Safety and Feasibility of Intrastromal Injection of Cultivated Human Corneal Stromal Keratocytes as Cell-Based Therapy for Corneal Opacities

Investigative ophthalmology & visual science, Jan 2, 2018

To evaluate the safety and feasibility of intrastromal injection of human corneal stromal keratoc... more To evaluate the safety and feasibility of intrastromal injection of human corneal stromal keratocytes (CSKs) and its therapeutic effect on a rodent early corneal opacity model. Twelve research-grade donor corneas were used in primary culture to generate quiescent CSKs and activated stromal fibroblasts (SFs). Single and repeated intrastromal injections of 2 to 4 × 104 cells to rat normal corneas (n = 52) or corneas with early opacities induced by irregular phototherapeutic keratectomy (n = 16) were performed, followed by weekly examination of corneal response under slit-lamp biomicroscopy and in vivo confocal microscopy with evaluation of haze level and stromal reflectivity, and corneal thickness using anterior segment optical coherence tomography (AS-OCT). Time-lapse tracing of Molday ION-labelled cells was conducted using Spectralis OCT and label intensity was measured. Corneas were collected at time intervals for marker expression by immunofluorescence, cell viability, and apoptos...

Research paper thumbnail of Application of a modified method for stem cell isolation from lipoaspirates in a basic lab

Medical Journal of Indonesia, 2009

... for sharing his invaluable expertise, to Boenjamin Setiawan, dr., PhD who delivered the idea ... more ... for sharing his invaluable expertise, to Boenjamin Setiawan, dr., PhD who delivered the idea of stem cell research, to the donors for donating their lipoaspirate, and the collaborated hospital staffs who have coordi-nated the material to be used in this ... Adi-pose-Derived Cells. ...

Research paper thumbnail of Immunogenicity characterization of mononucleated cells originated from umbillical cord blood

Medical Journal of Indonesia, 2010

Tujuan Sel punca yang diisolasi dari darah tali pusat diketahui merupakan populasi sel mononuklea... more Tujuan Sel punca yang diisolasi dari darah tali pusat diketahui merupakan populasi sel mononuklear yang terdapat dalam darah tali pusat. Hingga saat ini, telah banyak laporan mengenai penggunaan sel tipe ini sebagai alternatif transplantasi sel punca secara alogenik. Berdasarkan laporan beberapa hasil studi klinis, sel darah tali pusat dapat ditoleransi sekalipun pada kasus ketidakcocokan human leukocyte antigen (HLA) pada beberapa alel dengan jumlah kasus graft versus host reaction yang rendah. Penelitian ini mengkarakterisasi profil imunogenisitas sel mononuklear darah tali pusat yang diketahui banyak mengandung sel punca, melalui analisis reaksi alogenik yang ditimbulkannya dan dibandingkan dengan reaksi terhadap sel yang berasal dari darah tepi. Metode Aloreaktifitas dari darah tali pusat dianalisis dengan pemeriksaan mixed lymphocyte reaction (MLR) dilanjutkan dengan deteksi IFN-γ yang disekresikan ke dalam medium. Tipe HLA sel donor dan efektor diperiksa dengan pemeriksaan HLA berbasis PCR untuk menentukan reaktivitas alogenik. Lebih lanjut, tingkat ekspresi HLA kelas I dan II ditentukan dengan teknik flowcytometry menggunakan antibodi monoklonal terhadap kedua molekul tersebut. Hasil Dalam medium kultur MLR dengan sel darah tali pusat, ditemukan bahwa titer IFN-γ yang terdeteksi jauh lebih rendah daripada hasil MLR sel darah tepi. Hal ini menunjukan bahwa stimulasi alogenik yang ditimbulkan oleh sel darah tali pusat lebih rendah daripada darah tepi, sekaligus mengindikasikan rendahnya potensi rejeksi tipe sel tersebut. Hasil pemeriksaan tipe HLA menunjukkan bahwa hanya terdapat 1-3 kecocokan alel dari 8 alel pasangan sel yang digunakan dalam esai MLR. Lebih lanjut, ditemukan bahwa ekspresi molekul HLA kelas I pada sel darah tali pusat sangat rendah dan hanya sebagian kecil sel yang mengekspresikan HLA kelas II. Kesimpulan Studi ini mendemonstrasikan rendahnya imunogenisitas sel darah tali pusat melalui rendahnya IFN-γ yang disekresikan pada pemeriksaan MLR dan juga melalui rendahnya ekspresi molekul HLA kelas I serta lebih sedikitnya sel yang mengekspresikan HLA kelas II pada UCBMC. Hasil penelitian ini diharapkan akan menambah pemahaman mengenai pemanfaatan darah tali pusat sebagai sumber alternatif sel punca pada transplantasi alogenik.

Research paper thumbnail of Peran Molekul HLA dalam Proses Transplantasi Sel Punca

Jurnal Kedokteran Maranatha, 2010

Human Leukocyte Antigen (HLA) is the most important factor in determining the histocompatibility ... more Human Leukocyte Antigen (HLA) is the most important factor in determining the histocompatibility between the donor and the recipient in transplantation. HLA is a membrane-bound glycoprotein molecule encoded by several genes within chromosome 6 ...

Research paper thumbnail of Surface Modification of PMMA to Improve Adhesion to Corneal Substitutes in a Synthetic Core–Skirt Keratoprosthesis

ACS Applied Materials & Interfaces, 2015

Patients with advanced corneal disease do poorly with conventional corneal transplantation and re... more Patients with advanced corneal disease do poorly with conventional corneal transplantation and require a keratoprosthesis (KPro) for visual rehabilitation. The most widely used KPro is constructed using poly(methyl methacrylate) (PMMA) in the central optical core and a donor cornea as skirt material. In many cases, poor adherence between the PMMA and the soft corneal tissue is responsible for device "extrusion" and bacterial infiltration. The interfacial adhesion between the tissue and the PMMA was therefore critical to successful implantation and device longevity. In our approach, we modified the PMMA surface using oxygen plasma (plasma group); plasma followed by calcium phosphate (CaP) coating (p-CaP); dopamine followed by CaP coating (d-CaP); or plasma followed by coating with (3-aminopropyl)triethoxysilane (3-APTES). To create a synthetic KPro model, we constructed and attached 500 μm thick collagen type I hydrogel on the modified PMMA surfaces. Surface modifications produced significantly improved interfacial adhesion strength compared to untreated PMMA (p < 0.001). The p-CaP group yielded the best interfacial adhesion with the hydrogel (177 ± 27 mN/cm(2)) followed by d-CaP (168 ± 31 mN/cm(2)), 3-APTES (145 ± 12 mN/cm(2)), and plasma (119 ± 10 mN/cm(2)). Longer-term stability of the adhesion was achieved by d-CaP, which, after 14 and 28 days of incubation in phosphate buffered saline, yielded 164 ± 25 mN/cm(2) (p = 0.906 compared to adhesion at day 1) and 131 ± 20 mN/cm(2) (p = 0.053), respectively. In contrast, significant reduction of adhesion strength was observed in p-CaP group over time (p < 0.001). All surface coatings were biocompatible to human corneal stromal fibroblasts, except for the 3-APTES group, which showed no live cells at 72 h of culture. In contrast, cells on d-CaP surface showed good anchorage, evidenced by the expression of focal adhesion complex (paxillin and vinculin), and prominent filopodia protrusions. In conclusion, d-CaP can not only enhance and provide stability to the adhesion of collagen hydrogel on the PMMA surface but also promote biointegration.

Research paper thumbnail of S100A expression in normal corneal-limbal epithelial cells and ocular surface squamous cell carcinoma tissue

Molecular vision, 2011

To study the expression and cellular distribution of multiple S100A genes and proteins in normal ... more To study the expression and cellular distribution of multiple S100A genes and proteins in normal corneal-limbal epithelium and ocular surface squamous cell carcinoma (SCC) tissue. Normal corneal-limbal tissue was obtained from the Lions Eye Bank, Tampa, FL. Ocular surface SCC tissues were excised from patients undergoing surgery at Singapore National Eye Centre. S100A mRNA expression was measured by quantitative PCR. S100 protein distribution was determined by immunofluorescent staining analysis. Twelve S100 mRNAs were identified in human corneal and limbal epithelial cells. S100A2, A6, A8, A9, A10, and A11 mRNA was expressed at high level, while S100A1, A3, A4, A5, A6, A7, and A12 mRNA expression was low. The intracellular localization of S100A2, A6, A8, A9, A10 and A11 protein was determined in normal corneal-limbal and SCC tissues. S100A2 and S100A10 proteins were enriched in basal limbal epithelial cells of the normal tissue. S100A8 and S100A9 were found only at the surface of p...

Research paper thumbnail of Effectiveness of Antimicrobial Peptide Immobilization for Preventing Perioperative Cornea Implant-Associated Bacterial Infection

Antimicrobial Agents and Chemotherapy, 2014

Titanium (Ti) is a promising candidate biomaterial for an artificial corneal skirt. Antimicrobial... more Titanium (Ti) is a promising candidate biomaterial for an artificial corneal skirt. Antimicrobial peptide (AMP) immobilization may improve the bactericidal effect of the Ti substrate. In this study, we tested the bactericidal efficacy of a functionalized Ti surface in a rabbit keratitis model. A corneal stromal pocket was created by a femtosecond laser. The Ti films were then inserted into the pocket, and Staphylococcus aureus or Pseudomonas aeruginosa was inoculated into the pocket above the implant films. The corneas with Ti-AMP implants were compared with the corneas implanted with unprotected Ti by slit lamp observation and anterior segment optical coherence tomography (AS-OCT). Inflammatory responses were evaluated by bacterium counting, hematoxylin-eosin staining, and immunostaining. There was a lower incidence and a lesser extent of infection on rabbit corneas with Ti-AMP implants than on those with unprotected Ti implants. The bactericidal effect of AMP against S. aureus was comparable to that of postoperative prophylactic antibiotic treatment; hence, SESB2V AMP bound to the Ti implant provided functional activity in vivo, but its efficacy was greater against S. aureus than against P. aeruginosa. This work suggests that SESB2V AMP can be successfully functionalized in a rabbit keratitis model to prevent perioperative corneal infection.

Research paper thumbnail of Regulation of Toll-like receptor expression in human conjunctival epithelial cells

Mediators of inflammation, 2014

Previous studies showed marked decrease of multiple Toll-like receptor (TLR) expression in cornea... more Previous studies showed marked decrease of multiple Toll-like receptor (TLR) expression in corneal and conjunctival epithelial cells upon culture in vitro. The aim of this study was to identify factor(s) which regulate TLR expression. Primary human conjunctival epithelial cells and immortal conjunctival (IOBA-NHC) and corneal epithelial cell lines (HCET) were used. The effect of various cytokines, hypoxia, mechanical wounding, and airlifting culture on TLR expression was examined by quantitative PCR and western blot analysis. Ligand stimulated TLR activation was analyzed. TLR mRNA expression increased modestly when cultured monolayered cells were stimulated by TNF-α, IL-1α, IL-1β, IL-6, IL-8, IFN-γ (about 2-fold), hypoxia (2.1- to 4.8-fold selectively), and wounding (3.1- to 9.3-fold). In airlifted multilayered cells, TLR expression increased 7.8- to 25.9-fold compared to monolayered cells. Airlifted cells showed increased response to low concentrations of lipopolysaccharide (LPS) a...

Research paper thumbnail of Application of Graphene as Candidate Biomaterial for Synthetic Keratoprosthesis Skirt

Investigative Opthalmology & Visual Science, 2015

Synthetic keratoprostheses are required for visual rehabilitation in patients with end-stage corn... more Synthetic keratoprostheses are required for visual rehabilitation in patients with end-stage corneal blindness. This study aimed to assess the biocompatibility of graphene material and its potential as a novel synthetic keratoprosthesis skirt material for corneal tissue engineering. Human corneal stromal fibroblasts were cultured on material surfaces including pristine graphene film, graphene foam, pristine titanium (Ti) discs, and tissue culture plastic surface (TCPS). Cell attachment was assayed by immunostaining of paxillin and vinculin. Cell viability and proliferation were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and Click iT 5-ethynyl-2'-deoxyuridine (EdU) assays. The growth of fibroblasts on three-dimensional graphene foam was examined by scanning electron microscopy, and cytokine release was analyzed by enzyme-linked immunosorbent assay. Graphene films were implanted into rabbit corneal stromal pockets and examined by slit-lamp biomicroscopy, anterior segment optical coherence tomography, in vivo confocal microscopy, and histology. Pristine graphene demonstrated good biocompatibility with human stromal fibroblasts in terms of cell adhesion, viability, and proliferation. Cells on graphene films showed higher number than on TCPS control. Cells grown on graphene had 10% more proliferation than on Ti. The expression levels of IL-6 and IL-8 were reduced when cells were seeded on graphene foam as compared to Ti and graphene film. Implantation of graphene film into rabbit stroma (n = 6) did not show any signs of infection, neovascularization, or inflammation. Graphene displayed excellent short-term biocompatibility with corneal cells and tissue. This demonstrates that graphene can be developed as a tissue engineering material for use in cornea.