Vascularized adipose tissue engineering: moving towards soft tissue reconstruction

Abstract

Soft tissue defects are a common clinical challenge mostly caused by trauma, congenital anomalies and oncological surgery. Current soft tissue reconstruction (STR) options include synthetic materials (fillers and implants) and autologous adipose tissue transplantation through flap surgery and/or lipotransfer. Both reconstructive options hold important disadvantages to which vascularized adipose tissue engineering (VATE) strategies could offer solutions. In this review, we first summarized pivotal characteristics of functional adipose tissue (FAT) such as the structure, function, cell types, development and extracellular matrix (ECM). Next, we discussed relevant cell sources and how they are applied in different state-of-the-art VATE techniques. Herein, biomaterial scaffolds and hydrogels, ECMs, spheroids, organoids, cell sheets, 3D bioprinting and microfluidics are overviewed. Also, we included extracellular vesicles and emphasized their potential role in VATE. Lastly, current challenges and future perspectives in VATE are pointed out to help to pave the road towards clinical applications.

Hydrogel Based on Riclin Cross-Linked with Polyethylene Glycol Diglycidyl Ether as a Soft Filler for Tissue Engineering

“…An ideal tissue filler should also possess excellent biocompatibility, flexibility, and biological stability. 4,5,26 In general, hydrogels are designed using a suitable crosslinking agent to form irreversible covalent bonds with natural biomacromolecules. 27 The strategy ensures biocompatibility while enhancing the rheological properties and structural stabilities.…”

“…Normal structures of soft tissue are often depleted by loss of subcutaneous fat, collagen, and muscle resulting from tumor removals, traumatic injuries, lipoatrophy, congenital defects, and the aging process. − For the purpose of defect correction and esthetic application, a wide range of natural and artificial fillers have been extensively used in clinics for soft tissue augmentation. , Conventional permanent synthetic fillers often require invasive surgery to provide incisions for implantation procedures. , The risk of adverse reactions or complications may outweigh the potential benefits. , Autogenous adipose tissue exhibits great biocompatibility due to its entirely natural composition . However, fat grafting inevitably causes defects at the donor site and is limited to small volume restoration.…”

“…Subsequently, injectable hydrogels recover their original network structure and mechanical strength. An ideal tissue filler should also possess excellent biocompatibility, flexibility, and biological stability. ,, …”

Adipose tissue reconstruction facilitated with low immunogenicity decellularized adipose tissue scaffolds

“…Congenital defects, traumatic injuries, and tumor resections often result in soft tissue defects commonly due to the loss of subcutaneous adipose tissue, leading to alterations in the normal contour of the skin [1]. Data from the American Society for Plastic Surgery indicate that millions of soft tissue reconstructive and restorative surgeries are performed annually throughout the USA, with approximately 34% of these surgeries being related to cancer.…”

Decellularized extracellular matrix-based composite scaffolds for tissue engineering and regenerative medicine

“…The loss of tissue or organ integrity or function induced by trauma, disease, congenital anomalies and aging are common clinical challenges [ 1 , 2 ]. Although tissue transplantation is a promising strategy for restoring organ function in patients, severe immune rejection, suitable donor shortages and potential disease transmission remain inevitable challenges, limiting their applicability [ 3 , 4 ].…”