Integra Acellular Collagen as a Vascular Carrier for Skin Flap Prefabrication in Rats

Bioengineered smart trilayer skin tissue substitute for efficient deep wound healing

Skin substitutes for deep wound healing require meticulous designing and fabrication to ensure proper structural and functional regeneration of the tissue. Range of physical and mechanical properties conducive for regeneration of different layers of skin is a prerequisite of an ideal scaffold. However, single or bilayer substitutes, lacking this feature, fail to heal full thickness wound. Complete scar free regeneration of skin is still a big challenge. This study reports fabrication of a trilayer scaffold, from biodegradable polymers that can provide the right ambience for simultaneous regeneration of all the three layers of skin. The scaffold was developed through optimization of different fabrication techniques, namely, casting, electrospinning and lyophilisation, for obtaining a tailored trilayer structure. It has mechanical strength similar to skin layers, can maintain a porosity-gradient and provides microenvironments suitable for simultaneous regeneration of epidermis, dermis and hypodermis. A co-culture model, of keratinocytes and dermal fibroblasts, confirms the efficiency of the scaffold in supporting proliferation and differentiation of different types of cells, into organized tissue. The scaffold showed improved and expedited wound healing in-vivo. Taken together, these compelling evidences successfully established the engineered trilayer scaffold as a promising template for skin tissue regeneration in case of deep wound.

The use of urinary bladder matrix in the treatment of trauma and combat casualty wound care

Treatment of combat injuries and resulting wounds can be difficult to treat due to compromised and evolving tissue necrosis, environmental contaminants, multidrug resistant microbacterial and/or fungal infections, coupled with microvascular damage and/or hypovascularized exposed vital structures. Our group has developed surgical care algorithms with identifiable salvage techniques to achieve stable, definitive wound coverage often with the aid of certain regenerative medicine biologic scaffold materials and advanced wound care to facilitate tissue coverage and healing. This case series reports on the role of urinary bladder matrix scaffolds in the wound care and reconstruction of traumatic and combat wounds. Urinary bladder matrix was found to facilitate definitive soft tissue reconstruction by establishing a neovascularized soft tissue base acceptable for second stage wound and skin coverage options within traumatic and combat-related wounds.

Wound healing: an update

Wounds, both chronic and acute, continue to be a tremendous socioeconomic burden. As such, technologies drawn from many disciplines within science and engineering are constantly being incorporated into innovative wound healing therapies. While many of these therapies are experimental, they have resulted in new insights into the pathophysiology of wound healing, and in turn the development of more specialized treatments for both normal and abnormal wound healing states. Herein, we review some of the emerging technologies that are currently being developed to aid and improve wound healing after cutaneous injury.

Utilizing biologic assimilation of bovine fetal collagen in staged skin grafting

Seven patients underwent 2-stage skin grafting with bovine fetal collagen (BFC) as an initial wound cover. Split-thickness skin grafts were successfully placed on the wounds after completion of interval management. BFC proved to be a resilient acellular dermal matrix that could proceed to assimilation and skin grafting under a variety of wound conditions. BFC may prove to be a valuable material, as the role of acellular dermal matrices in skin grafting becomes better defined.

A novel strategy for creating a large amount of engineered fat tissue with an axial vascular pedicle and a prefabricated scaffold

In plastic and reconstructive surgery, there is a tremendous clinical need for adequate implants are needed to restore soft-tissue defects resulting from tumor resection, traumatic injury, or congenital anomalies. Restoring the aesthetic function of the soft tissue is as important as restoring the natural tissue function. To address aesthetic issues, injection of hyaluronic acid and collagen and use of artificially synthesized biomaterials and autologous fat tissue grafts is extensive in the clinic, still faces limitations. Achieving minimal morbidity while compensating contour irregularities remains a major challenge because the available reconstruction methods and unsatisfactory biomaterials. Adipose tissue engineering holds great promise for reconstruction, but so far, there was no reports of large-volume engineered adipose tissue. Construction of a large volume of vascularized engineered fat tissue may overcome clinical challenges because vascularization is essential for the survival of engineered fat tissue and its integration with the host tissue. An arteriovenous bundle model for soft tissue has been used in prefabricating a large volume fat tissue with axial vascularization in vivo. Therefore, we hypothesized that combining adipose tissue-derived stem cells (ASCs), and prefabricated vascularized collagen scaffolds, with perforated chamber and arteriovenous bundle, could generate a large volume of engineered fat tissue with an axial vascular pedicle in vivo. Like vascularized autologous tissue, the new constructs could be transferred to the defective site by local transference or microsurgical techniques. The novel strategy could provide a large volume of engineered fat tissue suitable for clinical application and new therapeutic strategies for reconstructing defects if the hypothesis proved to be practical.