Introducing aesthetic regenerative scaffolds: An immunological perspective

BACKGROUND

Skin aging arises from immunological responses to tissue deterioration and damage. Tissue repair processes encompass the regeneration of original tissue and 'scarless' wound healing seen in foetuses, and the extreme fibrotic responses and scarring seen in adults. Anti-aging aesthetic medicine uses interventions like biomaterial-based fillers to influence these immunological responses and renew aged tissue structure and function. At filler injection sites, an inflammatory response occurs that causes a spectrum of outcomes, ranging from tissue regeneration to fibrosis and filler encapsulation. Importantly, the resulting inflammatory pathway can be predetermined by the biomaterial injected.

AIMS

By understanding this immunological process, we can develop Aesthetic Regenerative Scaffolds (ARS) - aesthetic injectable biomaterials - to direct inflammatory wound healing away from chronic, fibrotic responses, and towards physiological tissue regeneration.

MATERIALS AND METHODS

We identified and reviewed literature on the immunological and cellular responses to injected dermal fillers, whereby the wound healing response to the injection was moderated under the influence of an injected biomaterial.

RESULTS

We described the mechanisms of dermal wound healing and the use of ARS to direct healing towards tissue regeneration instead of scarring. We also summarised studies on extracellular matrix remodeling by calcium hydroxylapatite. We found that Calcium hydroxylapatite fillers produce collagen as they gradually degrade and their spherical structures serve as a scaffold for tissue regeneration. Furthermore, CaHA improved fibroblast contractility, collagen type III and elastin production, proliferation and angiogenesis with less inflammation than hyaluronic acid fillers.

DISCUSSION

Regneration pathways can be influenced at specific points between a facial filler biomaterial and the wound healingmechanisms at its site of implantaion.

CONCLUSION

Physicians can select scaffolds that direct the immune response away from a fibrotic chronic inflammatory pathway and towards regeneration to enable true repair of the aging skin.

The evolving field of regenerative aesthetics

BACKGROUND

Regenerative aesthetics (RA) is an emerging subfield based on many of the principles of regenerative medicine (RM). In order to ensure that the development of regenerative aesthetics is based on accepted regenerative concepts and to optimize treatment strategies, it is important to establish clear definitions, fundamental aims and consider the impact of the predominant RA tissue environment RM focuses on the regeneration of injured or diseased tissue, while RA aims to restore youthful properties to aging, senescent tissue. The distinction is key in understanding how best to develop treatments for these different goals.

AIMS AND METHODS

The current review suggests key concepts, definitions, and foundations of regenerative aesthetic approaches and examines current evidence supporting this. It considers the importance of the aging tissue environment, the essential regenerative goals of restored tissue structure and function and introduces the concept of regenerative scaffolds with a focus on CaHA. Current techniques in the field and promising future directions are also discussed.

CONCLUSION

Regenerative aesthetics is an evolving subfield of regenerative medicine. Establishing clear definitions, identifying the challenges of the aging soft tissue environment and re-evaluating current evidence in light of regenerative goals are vital for the continuing evolution of this medical field.

Catching the aging curve early

In the field of Cosmetic Medicine, more and more younger individuals seek treatments and are looking further than only beautification and catching the aging curve early by improving the internal metabolism and strengthening the tissues. There is a promising niche evolving to meet these goals. The current article discussed one of the possibilities and techniques to catch this curve.

Mesenchymal Stem/Stromal Cell-Derived Exosomes for Immunomodulatory Therapeutics and Skin Regeneration

Exosomes are nano-sized vesicles that serve as mediators for cell-to-cell communication. With their unique nucleic acids, proteins, and lipids cargo compositions that reflect the characteristics of producer cells, exosomes can be utilized as cell-free therapeutics. Among exosomes derived from various cellular origins, mesenchymal stem cell-derived exosomes (MSC-exosomes) have gained great attention due to their immunomodulatory and regenerative functions. Indeed, many studies have shown anti-inflammatory, anti-aging and wound healing effects of MSC-exosomes in various in vitro and in vivo models. In addition, recent advances in the field of exosome biology have enabled development of specific guidelines and quality control methods, which will ultimately lead to clinical application of exosomes. This review highlights recent studies that investigate therapeutic potential of MSC-exosomes and relevant mode of actions for skin diseases, as well as quality control measures required for development of exosome-derived therapeutics.