Photoactivated Composite Biomaterial for Soft Tissue Restoration in Rodents and in Humans

Abstract

Soft tissue reconstruction often requires multiple surgical procedures that can result in scars and disfiguration. Facial soft tissue reconstruction represents a clinical challenge because even subtle deformities can severely affect an individual’s social and psychological function. We therefore developed a biosynthetic soft tissue replacement composed of poly(ethylene glycol) (PEG) and hyaluronic acid (HA) that can be injected and photocrosslinked in situ with transdermal light exposure. Modulating the ratio of synthetic to biological polymer allowed us to tune implant elasticity and volume persistence. In a small-animal model, implanted photocrosslinked PEG-HA showed a dose-dependent relationship between increasing PEG concentration and enhanced implant volume persistence. In direct comparison with commercial HA injections, the PEG-HA implants maintained significantly greater average volumes and heights. Reversibility of the implant volume was achieved with hyaluronidase injection. Pilot clinical testing in human patients confirmed the feasibility of the transdermal photocrosslinking approach for implantation in abdomen soft tissue, although an inflammatory response was observed surrounding some of the materials.

Role of tissue engineering in tendon reconstructive surgery and regenerative medicine: Current concepts, approaches and concerns

“…Also, the presence of many unknown zoonotic diseases in animals, about which we have no information, could be another major concern 6,8,9 . For the above reasons, tissue engineering has been introduced to reduce these limitations and improve the outcome of incorporation of the tissueengineered grafts and improve the healing processes of injured tendons 5,10,11 . In the last decade, tissue engineering has been improved and much advancement has been achieved 12,13 .…”

“…Biological characteristics of the scaffolds Biological characteristics are a major concern in the field of tendon tissue engineering 10,33 . At least five possible biological responses have been suggested after implantation of extra cellular matrixes including (i) ECM non-incorporating responses: (a) encapsulation; (b) rejection; and (ii) ECM-incorporating responses: (a) resorption; (b) integration with progressive degradation; (c) adoption and adaptation 7,8,37,44 .…”

Integrating Tissue Microenvironment with Scaffold Design to Promote Immune-Mediated Regeneration

“…Implants placed in the dorsal subcutaneous area of rats showed a decreased inflammatory response compared to those adjacent to adipose tissue in preliminary clinical trials [27]. This observation leads to further investigation of the location-regulated immune response through implantation of PEG hydrogels in varying locations of Sprague-Dawley rats [28].…”

Injectable Polyethylene Glycol Gel as Dermal Filler: 01 Year Clinical and Ultrasound Follow-Up

“…In medicine, it is topically used in cosmetics, suppositories, and for oral use in laxatives and tablets. It is also injectable in solutions for restoration of cartilaginous tissue [11] and subcutaneous tissue [12], due to its innocuousness and biodegradability [13].…”