The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform
Neeraj Kumar - One of the best experts on this subject based on the ideXlab platform.
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drug loaded polymeric Composite Skin Graft for infection free wound healing fabrication characterization cell proliferation migration and antimicrobial activity
2012Co-Authors: Anupama Mittal, Neeraj KumarAbstract:Purpose A new, injectable, drug-loaded Composite Graft was developed to enable infection free wound healing.
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drug loaded polymeric Composite Skin Graft for infection free wound healing fabrication characterization cell proliferation migration and antimicrobial activity
2012Co-Authors: Anupama Mittal, Neeraj KumarAbstract:A new, injectable, drug-loaded Composite Graft was developed to enable infection free wound healing. The Graft was fabricated using gentamicin and biomimetic microparticulate scaffolds in gelatin gel and characterized for biologically relevant properties like fluid uptake, evaporative water loss (EWL), water vapor transmission rate (WVTR), Young’s modulus and degradation. It was evaluated for drug release, cytocompatibility and antimicrobial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa. Graft exhibited fluid uptake of 13.79%, EWL of 60–70% in 10 h, WVTR of 5480.31 g/m2/d, and Young’s modulus as 2.1–10.8 kPa. It exhibited 99.36% degree of crosslinking and a dual degradation behavior wherein, the carrier gel, gelatin, degraded rapidly leaving the microparticulate scaffolds intact. Drug release studies showed a sustained release of gentamicin for 13 days sufficient to inhibit the infection at the wound site. Cytocompatibility assessment of the Graft revealed that Graft supported cell adhesion, proliferation and migration. The antibacterial efficacy of the Graft was assessed using Kirby-Bauer method and time kill assay, wherein results indicated a quick, effective (≥5-log reduction in CFU/ml) and long lasting antimicrobial effect. These results as a whole indicate that the Graft represents an effective alternative for infection-free healing of full thickness wounds.
Anupama Mittal - One of the best experts on this subject based on the ideXlab platform.
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drug loaded polymeric Composite Skin Graft for infection free wound healing fabrication characterization cell proliferation migration and antimicrobial activity
2012Co-Authors: Anupama Mittal, Neeraj KumarAbstract:Purpose A new, injectable, drug-loaded Composite Graft was developed to enable infection free wound healing.
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drug loaded polymeric Composite Skin Graft for infection free wound healing fabrication characterization cell proliferation migration and antimicrobial activity
2012Co-Authors: Anupama Mittal, Neeraj KumarAbstract:A new, injectable, drug-loaded Composite Graft was developed to enable infection free wound healing. The Graft was fabricated using gentamicin and biomimetic microparticulate scaffolds in gelatin gel and characterized for biologically relevant properties like fluid uptake, evaporative water loss (EWL), water vapor transmission rate (WVTR), Young’s modulus and degradation. It was evaluated for drug release, cytocompatibility and antimicrobial efficacy against Staphylococcus aureus and Pseudomonas aeruginosa. Graft exhibited fluid uptake of 13.79%, EWL of 60–70% in 10 h, WVTR of 5480.31 g/m2/d, and Young’s modulus as 2.1–10.8 kPa. It exhibited 99.36% degree of crosslinking and a dual degradation behavior wherein, the carrier gel, gelatin, degraded rapidly leaving the microparticulate scaffolds intact. Drug release studies showed a sustained release of gentamicin for 13 days sufficient to inhibit the infection at the wound site. Cytocompatibility assessment of the Graft revealed that Graft supported cell adhesion, proliferation and migration. The antibacterial efficacy of the Graft was assessed using Kirby-Bauer method and time kill assay, wherein results indicated a quick, effective (≥5-log reduction in CFU/ml) and long lasting antimicrobial effect. These results as a whole indicate that the Graft represents an effective alternative for infection-free healing of full thickness wounds.
Jeffrey R. Morgan - One of the best experts on this subject based on the ideXlab platform.
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contraction of the Composite Skin Graft and autoGraft
2002Co-Authors: Alfredo Gragnani, Jeffrey R. Morgan, Lydia Masako FerreiraAbstract:Wound contraction as a result of a delay in Grafting or second intention healing in an area that there was no Graft take is a serious problem because of the sequela to the burned patient.The objective of the present study was to evaluate the contraction of the cultured keratinocytes and human acellular dermis Composite Graft by tracing the Graft with transparent film after transplantation to the back of athymic mice.The evaluation of the contraction of the Composite Skin Grafts and autoGrafts in relation to the original wound area on the back of the athymic mice demonstrated greater contraction of the Grafts after the dressings were removed on the seventh day. The Composite Skin Graft contraction was significantly bigger than the autoGraft contraction.The experimental data suggested that the contraction appeared after dressing removal, but that the macroscopic aspect of the Composite Skin Graft remained normal with no distortion of the Graft or the surrounded murine Skin.
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differentiation and barrier formation of a cultured Composite Skin Graft
2002Co-Authors: Alfredo Gragnani, Jeffrey R. Morgan, Lydia Masako FerreiraAbstract:The differentiation and barrier formation of cultured Composite Skin Grafts (CSGs) were assessed by histology and measurements of surface electrical capacitance (SEC) in vitro and in vivo. Keratinocytes cultured on the surface of acellular dermis were lifted to the air-liquid interface and analyzed for 30 days in vitro. Initially, SEC measurements of CSGs (n = 11) were high but quickly dropped between days 4 and 6 and remained steady for 30 days, indicating barrier formation by the epidermis. Histology of the CSGs (n = 6) demonstrated stratification of the epidermal cells and partial formation of the stratum corneum by day 3 that was complete by day 7. CSGs (n = 5) were transplanted to athymic mice, where they formed a stratified and differentiated epidermis. SEC measurements of CSGs remained low after transplant, suggesting that exposure to the air-liquid interface improved the maturation of CSGs in vitro prior to transplant.
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genetically modified human keratinocytes overexpressing pdgf a enhance the performance of a Composite Skin Graft
1998Co-Authors: Sabine A Eming, Daniel A. Medalie, Ronald G. Tompkins, Martin L Yarmush, Jeffrey R. MorganAbstract:ABSTRACT Skin loss due to burns and ulcers is a major medical problem. Bioengineered Skin substitutes that use cultured keratinocytes as an epidermal layer with or without analogues of the dermis are one strategy for Skin repair. However, none can achieve definitive wound closure, function, or cosmesis comparable to split-thickness autoGrafts. Moreover, autoGraft donor sites, which require time to heal, may be limited or have attendant problems such as infection or functional/cosmetic deficiencies. To determine if the performance of Composite Skin Grafts of keratinocytes on a dermal analogue could be enhanced, human keratinocytes were genetically modified to overexpress platelet-derived growth factor A chain (PDGF-A). Composite Grafts of modified keratinocytes seeded onto acellular dermis, prepared from cryopreserved cadaver Skin, secreted PDGF-AA protein in vitro [90 ng/Graft (1.5 × 1.5 cm)/24 hr]. To test their performance in a wound healing model, Composite Grafts were transplanted to full-thickness ex...
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Evaluation of acellular human dermis as a dermal analog in a Composite Skin Graft.
1996Co-Authors: Daniel A. Medalie, Ronald G. Tompkins, Jeffrey R. MorganAbstract:: This study evaluated the structure and function of a dermal substitute composed of de-epidermalized, acellular human dermis, and tested its performance as part of a Composite Skin Graft with cultured human keratinocytes. The acellular dermis retained much of the complex structure of native dermis, as demonstrated by immunostaining for collagen Types IV and VII. Collagen Types IV and VII were found on the papillary surface, and collagen Type IV was found at sites throughout the acellular dermis. To further demonstrate the functionality of the acellular dermis material, we seeded the papillary surface with cultured keratinocytes. In response to the architecture of the dermal papillae, the keratinocytes formed a three-dimensional epidermal structure that was several cell layers thick, and recreated the original Skin rete ridges at the interface with the dermis. When these Composite Grafts were transplanted to athymic mice, host fibrovascular cells repopulated the acellular dermis. Some vessels grew into the acellular dermis along the original pathways of the human blood vessels, as demonstrated by co-localization of human and mouse collagen Type IV. The Skin that developed from these Grafts repigmented completely via passenger melanocytes from the keratinocyte cultures, was durable, and remained stable for more than 5 months.
J F Hansbrough - One of the best experts on this subject based on the ideXlab platform.
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use of a Composite Skin Graft composed of cultured human keratinocytes and fibroblasts and a collagen gag matrix to cover full thickness wounds on athymic mice
1991Co-Authors: M L Cooper, J F HansbroughAbstract:In patients with extensive full-thickness burns, wound coverage may be accelerated if Skin can be expanded to produce a Skin replacement that reproducibly supplies blood to the wound and has good structural qualities. In addition, development of Skin replacements may benefit patients who require reconstruction or replacement of large areas of abnormal Skin. We have developed a Composite Skin replacement composed of cultured human keratinocytes (HK) and fibroblasts. Cultured human fibroblasts are seeded into the interstices, and cultured HKs are applied to the surface of a matrix composed of type I collagen crosslinked with a glycosaminoglycan, which has a defined physical structure. After HKs reach confluence on the matrix surface, the Composite Grafts are placed on full-thickness wounds on the dorsum of athymic mice. Graft acceptance, confirmed by positive staining with antibodies specific for human HLA-ABC antigens on HKs, is approximately 90%. A defined Skin structure is present histologically by day 10 after Grafting, with a differentiated epithelium and a subepidermal layer densely populated by fibroblasts and capillaries without evidence of inflammation. Fluorescent light microscopy to identify laminin and type IV collagen and electron microscopy confirm the presence of basement membrane components by 10 days after Grafting. Attachment of the Graft to the wound is similar with and without the addition of human basic fibroblast growth factor, a potent angiogenic agent, to the Skin replacement before Graft placement on wounds.
M L Cooper - One of the best experts on this subject based on the ideXlab platform.
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use of a Composite Skin Graft composed of cultured human keratinocytes and fibroblasts and a collagen gag matrix to cover full thickness wounds on athymic mice
1991Co-Authors: M L Cooper, J F HansbroughAbstract:In patients with extensive full-thickness burns, wound coverage may be accelerated if Skin can be expanded to produce a Skin replacement that reproducibly supplies blood to the wound and has good structural qualities. In addition, development of Skin replacements may benefit patients who require reconstruction or replacement of large areas of abnormal Skin. We have developed a Composite Skin replacement composed of cultured human keratinocytes (HK) and fibroblasts. Cultured human fibroblasts are seeded into the interstices, and cultured HKs are applied to the surface of a matrix composed of type I collagen crosslinked with a glycosaminoglycan, which has a defined physical structure. After HKs reach confluence on the matrix surface, the Composite Grafts are placed on full-thickness wounds on the dorsum of athymic mice. Graft acceptance, confirmed by positive staining with antibodies specific for human HLA-ABC antigens on HKs, is approximately 90%. A defined Skin structure is present histologically by day 10 after Grafting, with a differentiated epithelium and a subepidermal layer densely populated by fibroblasts and capillaries without evidence of inflammation. Fluorescent light microscopy to identify laminin and type IV collagen and electron microscopy confirm the presence of basement membrane components by 10 days after Grafting. Attachment of the Graft to the wound is similar with and without the addition of human basic fibroblast growth factor, a potent angiogenic agent, to the Skin replacement before Graft placement on wounds.