Anti-aging strategies using topicals with active agents demand validation and proof of efficacy. One investigation in this realm involves gene expression testing. This study undertakes gene expression analysis of Alastin Skincare Regenerating Skin Nectar (RSN) using an in vitro human skin model. The current study is similar to other published human skin model studies, but with additional time periods beyond 24-hours (which are more appropriate for testing peptides) and a suitable control for the Alastin non-aqueous product. Results show the Alastin product upregulates a large array of genes within areas of skin renewal, extracellular matrix remodeling, barrier function, and inflammation after 72 hours. The study provides gene expression data that support the clinical success of the product. It also demonstrates the difficulty and vulnerabilities in assessing efficacies of products with certain in vitro investigations when the nuances of that product are not considered. J Drugs Dermatol. 2019;18(12):1255-1259.

Background

Photodamage creates changes within the skin layers known as solar elastosis. This presents as fragmentation of collagen and elastin fibers, decreases in the extracellular matrix (ECM) ground substance, as well as hyaluronic acid decrease in the thinning epidermis. Traditional immunohistochemistry (IHC) staining has failed to differentiate degenerated elastin from new elastin fibers generated with various topical strategies.

Aims

A combination of stains that can offer a regenerative narrative distinguishing newly formed collagen and elastin from that of degenerated protein, thus distinguishing "good" vs "bad" elastin.

Methods

A series of stains were explored based on their ability to identify early regenerative changes within epidermal, dermal, and ECM areas to examine consistency of outcomes and reliability.

Results

A combination of Movat, fibrillin, elafin, and versican for elastogenesis and reversal of solar elastosis. CD44 for HA status (mainly epidermal) and Herovici stain for identifying early collagenesis in the ECM provides a comprehensive range of stains for identifying new elastin and collagen CONCLUSION: This suggested stain combination appears to offer an ideal collection of stains for identifying regenerative events within the skin layers.

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells (MSCs) that possess many of the same regenerative properties as other MSCs. However, the ubiquitous presence of ADSCs and their ease of access in human tissue have led to a burgeoning field of research. The plastic surgeon is uniquely positioned to harness this technology because of the relative frequency in which they perform procedures such as liposuction and autologous fat grafting. This review examines the current landscape of ADSC isolation and identification, summarizes the current applications of ADSCs in the field of plastic surgery, discusses the risks associated with their use, current barriers to universal clinical translatability, and surveys the latest research which may help to overcome these obstacles.

Background

Stem cells are a unique cell population characterized by self-renewal and cellular differentiation capabilities. These characteristics, among other traits, make them an attractive option for regenerative treatments of tissues defects and for aesthetic procedures in plastic surgery. As research regarding the isolation, culture and behavior of stem cells has progressed, stem cells, particularly adult stem cells, have shown promising results in both translational and clinical applications.

Methods

The purpose of this review is to evaluate the applications of stem cells in the plastic surgery literature, with particular focus on the advances and limitations of current stem cell therapies. Different key areas amenable to stem cell therapy are addressed in the literature review; these include regeneration of soft tissue, bone, cartilage, and peripheral nerves, as well as wound healing and skin aging.

Results

The reviewed studies demonstrate promising results, with favorable outcomes and minimal complications in the cited cases. In particular, adipose tissue derived stem cell (ADSC) transplants appear to provide effective treatment options for bony and soft tissue defects, and non-healing wounds. ADSCs have also been shown to be useful in aesthetic surgery.

Conclusions

Further studies involving both the basic and clinical science aspects of stem cell therapies are warranted. In particular, the mechanism of action of stem cells, their interactions with the surrounding microenvironment and their long-term fate require further elucidation. Larger randomized trials are also necessary to demonstrate the continued safety of transplanted stem cells as well as the efficacy of cellular therapies in comparison to the current standards of care.

This paper introduces the concept of "skin bed preparation" prior to surgical procedures. Following the theory of chronic wound bed preparation and adapting the skin model to one of chronic wound changes related to extrinsic and intrinsic factors, a topical formulation aimed at recycling the extracellular matrix (ECM) from accumulated waste products is evaluated and discussed. The clearance of these products and stimulation of new replacements has the potential to change the regenerative milieu of the skin so that when procedures are carried out, cellular signaling and cross-talk at the dermal level are improved and healing is optimized. By introducing a combination of peptides and other synergistic active agents, a sequence of clearance, regeneration, and remodeling is initiated. This is confirmed and validated by a series of biopsies and clinical studies that demonstrate changes in the ECM as early as 2 to 3 weeks after application. Clinical studies related to resurfacing procedures show accelerated healing and improved symptomatic relief compared with standard of care by preconditioning the skin 2 weeks prior to the procedure. A similar approach is suggested as a potential advantage for invasive surgical procedures based on similar scientific principles elucidated on in the text.

Background

This paper describes the background research and validation related to the formulation of a novel antioxidant product. Two defined outcomes were sought. Firstly, a combined efficacy of antioxidant ingredients in quenching free oxygen radicals. Secondly, the investigation into whether a vitamin C derivative sodium salt was elastin conserving in contrast to current vitamin C/l-ascorbic acid variations that have been reported to negatively affect elastin constitution and regeneration.

Materials and methods

A leading l-ascorbic acid antioxidant available on the market was compared with the experimental new product in two studies. In the first experiment, the products were compared to assess their antioxidant properties. The evaluated products TOPICAL ANTIOXIDANT 1 and TOPICAL ANTIOXIDANT 2 were applied to human skin cultures (25-30 mg/cm² ) for a total of 72 h of treatment and exposed to oxidative stress. The generation of free radicals was semi-quantitatively assessed by measuring the fluorescence intensity of the deacetylation and oxidation of the probe dichlorofluorescein diacetate (DCFH-DA). In the second experiment, an ex vivo skin model (derived from patients undergoing facelift procedures) was used to assess elastin preservation. Three skin explants were topically subjected to the two formulations daily for 7 days. The skin was then prepared and fixed for immunofluorescent assessment after staining with CD44 and tropoelastin antibodies. Images were then analyzed using ImageJ.

Results

A full description of the different components selected for the new formulation is presented. In the first study, the experimental formulation performed with absolute equivalence to the comparator in its radical quenching capacity; both showed extremely effective antioxidant function. In the second study, the comparator negatively affected the existing elastin with areas of breakdown and diminished staining. In contrast, the new formulation showed good conservation of healthy elastin in all sections demonstrating elastin preservation.

Conclusion

A new antioxidant formulation was carefully designed with multiple actives that show an equivalent antioxidant capacity to a leading product on the market. More importantly, the vitamin C component shows direct elastin conservation and improvement as opposed to the comparator, which had negative effects on elastin preservation. This is in keeping with little-known literature reports on vitamin C and its negative effects on elastin and validates the use of a sodium salt derivative, which appears to have protective effects on elastin. These findings support the overall regenerative extracellular matrix changes seen with TriHex® technology in other products.

Background

Adipose tissue is an easily accessible source of stem and progenitor cells that offers exciting promise as an injectable autologous therapeutic for regenerative applications. Mechanical processing is preferred over enzymatic digestion, and the most common method involves shuffling lipoaspirate between syringes and filtering to produce nanofat. Although nanofat has shown exciting clinical results, the authors hypothesized that new device designs could enhance recovery of stem/progenitor cells through optimization of fluid dynamics principles, integration, and automation.

Methods

The authors designed and fabricated the emulsification and micronization device (EMD) and the filtration device (FD) to replace the manual nanofat procedures. Using human lipoaspirate samples, the EMD and the FD were optimized and compared to traditional nanofat using ex vivo measurements of cell number, viability, and percentage of mesenchymal stem cells and endothelial progenitor cells.

Results

The EMD produced results statistically similar to nanofat, and these findings were confirmed for a cohort of diabetic patients. Combining the FD with the EMD was superior to manually filtered nanofat in terms of both recovered cell percentages (>1.5-fold) and numbers (two- to three-fold). Differences were statistically significant for total mesenchymal stem cells and a DPP4 + /CD55 + subpopulation linked to improved wound healing in diabetes.

Conclusions

The new EMD and the FD improved mechanical processing of human lipoaspirate in terms of mesenchymal stem cell enrichment and number compared to traditional nanofat. Future work will seek to investigate the wound healing response both in vitro and in vivo, and to refine the technology for automated operation within clinical settings.

Clinical relevance statement

The new devices improved mechanical processing of human lipoaspirate in terms of stem cell enrichment and number compared to traditional methods. Future work will seek to validate wound healing response and refine the technology for automated operation within clinical settings.

Peripheral nerve injury requiring nerve gap reconstruction remains a major problem. In the quest to find an alternative to autogenous nerve graft procedures, attempts have been made to differentiate mesenchymal stem cells into neuronal lineages in vitro and utilize these cellular constructs for nerve regeneration. Unfortunately, this has produced mixed results, with no definitive procedure matching or surpassing traditional nerve grafting procedures. This review presents a different approach to nerve regeneration. The literature was reviewed to evaluate current methods of using adipose-derived stem cells (ADSCs) for peripheral nerve regeneration in in vivo models of animal peripheral nerve injury. The authors present cited evidence for directing nerve regeneration through paracrine effects of ADSCs rather than through in vitro nerve regeneration. The paracrine effects rely mainly, but not solely, on the elaboration of nerve growth factors and neurotrophic mediators that influence surrounding host cells to orchestrate in vivo nerve regeneration. Although this paradigm has been indirectly referred to in a host of publications, few major efforts for this type of neuromodulatory nerve regeneration have been forthcoming. The ADSCs are initially "primed" in vitro using specialized controlled medium (not for neuronal differentiation but for sustainability) and then incorporated into a hydrogel base matrix designed for this purpose. This core matrix is then introduced into a natural collagen-based nerve conduit. The prototype design concepts, evidence for paracrine influences, and regulatory hurdles that are avoided using this approach are discussed.

There has been much debate concerning the pathologic consequences of diabetes on the plantar fat pad and its subsequent association with the development of a foot ulcer. This review article documents two theories regarding pathophysiology in diabetic foot ulcer formation as they are related to the plantar fat pad and discusses current treatment options for this pathophysiological phenomenon. Traditionally, fat pad atrophy in diabetic patients was thought to result as an irregular arrangement of collagen fibrils within the septal walls as a result of glycation as well as diminishing adipocyte size due to thickened septal walls. Contrary to this traditional theory, a model depicting distal fat pad migration from under the metatarsal heads has been described in the diabetic patient. Such pad migration renders the metatarsal heads vulnerable to increased pressure, which, in turn, predisposes to foot ulceration. This migratory fat pad theory plays a significant role in approaches to the prevention of diabetic foot ulceration and subsequent amputation. Various methods of fat pad supplementation and claw toe management are impacted by the pathophysiological changes described and new avenues of therapy may be based on these changes.

TriHex Technology (Alastin Skincare, Carlsbad, CA) has been shown clinically to promote healing and outcomes post procedures and has been demonstrated clinically to improve lipid droplet dissolution and patient-reported outcomes post procedure. Histologically, the formulations have proven to regenerate collagen and elastin. The use of the technology to prepare the skin for surgical procedures combined with its use post procedure was assessed through clinical study outcomes, histological evidence, and gene expression analyses and demonstrated remodeling of the extracellular matrix (ECM), accelerating healing, and initiation of anti-inflammatory genes. While the improvement in clinical signs and outcomes has been validated, the changes taking place at a molecular level need to be explored. The interaction of cells (adipocytes, macrophages, fibroblasts) and the ECM proteins (collagen, elastin) secondary to the effects of the topical agent application are discussed. It appears that the manipulation of fat during body contouring surgery and the resultant adipocytolysis precipitates a molecular profile that can be positively directed toward hastened healing by using adjuvant topical applications as preconditioning prior to surgery and after the surgical procedure. Here, we review the literature and underlying physiology relating to these products and describe how interleukin 6 appears to be the primary facilitator of these effects.