Protocols for full thickness skin wound repair using prevascularized human mesenchymal stem cell sheet

© Springer Science+Business Media New York 2018. Split thickness skin grafts (STSGs) are one of the standard treatments available for full thickness wound repair when full thickness grafts (FTGs) are not viable, such as in the case of wounds with large surface areas. The donor sites of STSGs may be harvested repeatedly, but STSG transplants are still limited by insufficient blood supply at the early stages of wound healing. Prevascularized human mesenchymal stem cell (hMSC) sheets may accelerate wound healing and improve regeneration by providing preformed vessel structures and angiogenic factors to overcome this limitation. This book chapter provides the protocol of co-culturing hMSCs and endothelial cells to attain a prevascularized hMSC cell sheet (PHCS). The protocols for implantation of the prevascularized stem cell sheet for full thickness skin wound repair in a rat autologous skin graft model as well as the evaluation of the wound healing effects are also provided

Wound Dressings: A Comprehensive Review

This comprehensive review covers the advantage and limitations of some dressing materials and the current knowledge on wound dressings and emerging technologies to achieve proper wound healing.Traditional and modern dressings are helpful in the wound healing process; however, they cannot substitute lost tissue. Human skin equivalents have been developed conceptually to fill this void as they do not only facilitate wound healing but also may replace lost tissue. Several studies have shown that the addition of mesenchymal stem cells, such as in human placenta, has promising results in wound healing.A wound is defined as a disruption in the continuity of the skin or mucosa due to physical or thermal damage, or an underlying medical condition. Wound healing is a complex, dynamic, and multistep process which occurs after skin damage leading to tissue repair. Although the skin normally undergoes repair after a disruption, the healing process can be affected in different conditions such as diabetes mellitus, infections, venous/arterial insufficiency, among others. To enhance healing, a wide range of wound dressings are available; however, a thorough wound assessment (e.g., wound type, size, depth, or color) is required to choose the appropriate dressing. The emergence of new dressings has brought a new perspective of wound healing, but there is no superior product yet to treat acute and/or chronic wounds. Therefore, wound dressing research studies need to be carried out in order to help improve wound healing

Potential of Natural Biomaterials in Nano-scale Drug Delivery

Background: The usage of natural biomaterials or naturally derived materials intended for interface with biological systems has steadily increased in response to the high demand of amenable materials, which are suitable for purpose, biocompatible and biodegradable. There are many naturally derived polymers which overlap in terms of purpose as biomaterials but are equally diverse in their applications. Methods: This review examines the applications of the following naturally derived polymers; hyaluronic acid, silk fibroin, chitosan, collagen and tamarind polysaccharide (TSP); further focusing on the biomedical applications of each as well as emphasising on individual novel applications. Results: Each of the polymer was found to demonstrate a wide variety of successful biomedical applications fabricated as wound dressings, scaffolds, matrices, films, sponges, implants or hydrogels to suit the therapeutic need. Interestingly, blending and amelioration of polymer structures were but two of a selection of strategies to modify the functionality of the polymers to suit the purpose. Further these polymers have shown promise to deliver small molecule drugs, proteins and genes as nano-scale delivery systems. Conclusion: The review highlights the breadth and depth of applications of the aforementioned polymers as biomaterials. Hyaluronic acid, silk fibroin, chitosan, collagen and TSP have been successfully utilised as biomaterials in the subfields of implant enhancement, wound management, drug delivery, tissue engineering and nanotechnology. Whilst there are a number of associated advantages (i.e. biodegradability, biocompatibility, non-toxic, non-antigenic as well as amenability) the select disadvantages of each individual polymer provide significant scope for their further exploration and overcoming challenges like feasibility of mass production at a relatively low cost