Collagen Stimulators

Tailoring biomaterials for skin anti-aging

Skin aging is the phenomenon of degenerative changes in the structure and function of skin tissues over time and is manifested by a gradual loss of skin elasticity and firmness, an increased number of wrinkles, and hyperpigmentation. Skin anti-aging refers to a reduction in the skin aging phenomenon through medical cosmetic technologies. In recent years, new biomaterials have been continuously developed for improving the appearance of the skin through mechanical tissue filling, regulating collagen synthesis and degradation, inhibiting pigmentation, and repairing the skin barrier. This review summarizes the mechanisms associated with skin aging, describes the biomaterials that are commonly used in medical aesthetics and their possible modes of action, and discusses the application strategies of biomaterials in this area. Moreover, the synergistic effects of such biomaterials and other active ingredients, such as stem cells, exosomes, growth factors, and antioxidants, on tissue regeneration and anti-aging are evaluated. Finally, the possible challenges and development prospects of biomaterials in the field of anti-aging are discussed, and novel ideas for future innovations in this area are summarized.

Revitalizing the lower face: Therapeutic insights and an innovative treatment guideline for jowl rejuvenation

BACKGROUND

The intricate mechanisms of jowl formation, which ultimately lead to loss of lower jaw definition, skin laxity, and localized fat accumulation, involve interrelated factors such as skin aging, fat redistribution, muscle dynamics, and loss of support.

AIMS

To propose a structured approach to the treatment of the jowl area that is comprehensive and tailored to the needs of each individual patient.

MATERIALS AND METHODS

This integrative review combines a meticulous analysis of the literature with practical insights from real-world clinical settings. The authors draw on their extensive clinical experience to bridge research findings with practical clinical perspectives.

RESULTS

This study presents a guideline for addressing jowl formation that starts with the major aging processes and, based on simple diagnostic questions, suggests minimally invasive interventions, including collagen stimulators, energy-based devices, lipolytic injectables, polydioxanone threads, and hyaluronic acid fillers.

DISCUSSION

The guideline emphasizes the significance of personalized treatments while also acknowledging the need for comprehensive evaluation and recognizing the ever-evolving nature of aesthetic interventions in jowl management.

CONCLUSION

This systematic approach can not only simplify diagnostic and treatment decisions for dermatologists but also enhance patient satisfaction by customizing treatment plans based on individual characteristics and expectations.

Poly-l-lactic acid microspheres delay aging of epidermal stem cells in rat skin

Objective

Injectable skin fillers offer a wider range of options for cutaneous anti-aging and facial rejuvenation. PLLA microspheres are increasingly favored as degradable and long-lasting fillers. The present study focused solely on the effect of PLLA on dermal collagen, without investigating its impact on the epidermis. In this study, we investigated the effects of PLLA microspheres on epidermal stem cells (EpiSCs).

Methods

Different concentrations of PLLA microspheres on epidermal stem cells (EpiSCs) in vitro through culture, and identification of primary rat EpiSCs. CCK-8 detection, apoptosis staining, flow cytometry, Transwell assay, wound healing assay, q-PCR analysis, and immunofluorescence staining were used to detect the effects of PLLA on EpiSCs. Furthermore, we observed the effect on the epidermis by injecting PLLA into the dermis of the rat skin in vivo.

Results

PLLA microspheres promote cell proliferation and migration while delaying cell senescence and maintaining its stemness. In vitro, Intradermal injection of PLLA microspheres in the rat back skin resulted in delayed aging, as evidenced by histological and immunohistochemical staining of the skin at 2, 4, and 12 weeks of follow-up.

Conclusion

This study showed the positive effects of PLLA on rat epidermis and EpiSCs, while providing novel insights into the anti-aging mechanism of PLLA.

Safety and Efficacy of Diluted Calcium Hydroxylapatite for the Treatment of Cellulite Dimpling on the Buttocks: Results from an Open-Label, Investigator-Initiated, Single-Center, Prospective Clinical Study

BACKGROUND

Cellulite is a condition characterized by dimpling and contour irregularities in the gluteal and thigh regions, affecting an estimated 80-98% of postpubertal women. Innovative treatments for cellulite dimpling in the buttocks have gained popularity in recent years, seeking new solutions for a historically challenging condition. In this open-label, investigator-initiated, single-center, prospective clinical study, the authors sought to evaluate the safety and efficacy of diluted calcium hydroxylapatite (CaHA; Radiesse®, Merz Aesthetics, Raleigh, NC) for the treatment of cellulite dimpling in the buttocks of adult women.

METHODS

Subjects underwent three treatment sessions, receiving a total of 12 syringes of 1:1 diluted CaHA administered using a cannula-based subcision technique. Endpoints included the cellulite severity scale (CSS), the global aesthetic improvement scale (GAIS), subject satisfaction measured on a 5-point scale, and three-dimensional imaging analysis via the Quantificare 3D Track®.

RESULTS

Twenty-four subjects completed the study (mean age, 35 years; mean BMI, 26.88 kg/m2; mean body fat percentage, 31.29%), and no serious complications were reported. Quantitative analysis at week 14 revealed a mean reduction of 54.0% in the number of visible dimples and 50.09% in dimple depth compared to baseline. The mean CSS score decreased by 4.29 points, representing a 43.92% improvement in cellulite severity from baseline (p < 0.0001). Both physician-assessed and subject-assessed GAIS ratings also demonstrated significant improvement, with 91.6% of subjects rating their cellulite appearance as "improved" or greater.

CONCLUSION

The results of this study support the safety and efficacy of diluted CaHA for treating cellulite dimpling in adult women.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

CLINICAL TRIALS REGISTRATION

This study is registered with clinicaltrials.gov (ID: NCT05885035) and can be found at this link: https://clinicaltrials.gov/study/NCT05885035 .

The emerging role of biostimulators as an adjunct in facial rejuvenation: A systematic review

INTRODUCTION

Facial aging has long been an area of focus in esthetic surgery. It is the consequence of physiologic and environmental factors, with a trend toward non-surgical modalities. Although volume augmentation has long been a focus of non-surgical facial rejuvenation, there is emerging interest in the use of biostimulators to induce physiologic changes in the skin. This article aimed to provide an overview of this class of therapies.

METHODS

A systematic review regarding the clinical use of biostimulatory agents including platelet-rich plasma (PRP), platelet-rich fibrin (PRF), poly-L-lactic acid (PLLA) and calcium hydroxylapatite (CaHA) in facial rejuvenation was performed using PubMed databases. The protocol was developed following the preferred reporting for items for systematic reviews-protocols guidelines. Included studies matched predetermined criteria according to the employed intervention and outcomes.

RESULTS

The systematic review was performed in September 2023, with the primary search yielding 464 articles. Abstract review resulted in 73 articles of potential relevance. Comprehensive review of the articles and manual reference checks were performed, independently, by 2 authors. This yielded a total of 45 articles that met the inclusion criteria.

CONCLUSIONS

There is an increasing role for non-surgical modalities in facial rejuvenation. Biostimulatory agents may be used as an alternative, or act as an adjunct, to other non-surgical modalities. These agents induce physiologic changes that mitigate facial aging. There is limited, quantifiable data, which fully illustrate the effect in these products. Although these agents are known to illicit inflammatory changes, more controlled studies are needed to better elucidate the biostimulatory capacity of such non-surgical treatments.

Effect of poly-L-lactic acid and polydioxanone biostimulators on type I and III collagen biosynthesis

OBJECTIVE

Safe, effective, and biocompatible minimally invasive procedures with the potential to stimulate collagen production have been made to recover dermal thickness and skin quality. The main of this animal model experiment was to observe the effect of poly-L-lactic acid (PLLA) and polydioxanone (PDO) biostimulators in collagen I and III after hypodermal injection.

METHODOLOGY

Sixteen adult female rats (Wistar) were randomized into four groups and had dorsal treatment with: G1: hypodermic subcision (HS) only; G2: HS and PLLA hypodermic injection (HI), G3: HS and PDO HI; G4: Control, with no treatment.

RESULTS

In histochemical, it was observed hypodermal and dermal tissue in more organized thickness in G3 and in G4 when compared to G1 and G2. There was few difference in G1 compared to G4. The tissue of G2 showed irregularities in the arrangement of collagen fibers, less defined structure and lower distribution of type I collagen compared to the other groups. There is a greater tendency for the proportions of type III collagen among tissues treated with both biostimulators (G2 and G3). PLLA and PDO had relatively similar percentages of collagen when compared to G4. The amount of type I collagen was higher in tissues treated with subcision, while type III collagen was higher in tissues treated with both biostimulators.

CONCLUSION

G3 showed better performance in collagen production, although small, when compared with G2.

Application of PLLA (Poly-L-Lactic acid) for rejuvenation and reproduction of facial cutaneous tissue in aesthetics: A review

Poly-L-lactin acid (PLLA) has been widely used in the field of bio-medicine. In 2004, as an injectable material, PLLA was approved by the FDA to treat AIDS-related facial atrophy. Since then, several injectable stuffs containing PLLA have been approved for marketing in various countries and regions. Recently, PLLA has often been used to treat facial rejuvenation problems like cutaneous depressions and static wrinkles which always induce unsatisfactory facial expression. This review introduces the physicochemical properties, regeneration stimulating mechanism, applications in aesthetics and injectable comorbidity of PLLA.

Minimally invasive cosmetic procedures for mothers of brides: Strategies and considerations

The pivotal role of the bride's mothers in wedding celebrations is an effective motivation to seek cosmetic therapies, making them frequent patients in a dermatologists' offices. Addressing their aesthetic concerns contributes to their holistic well-being, but faces an intricate relationship between time availability, financial factors, and the critical emotional context. This article underscores the varying behavioral patterns of mothers of brides when seeking aesthetic treatments, providing tailored strategies for effective communication and decision-making, based on individual personalities. Additionally, this paper presents a specific timeline for the implementation of these interventions, including neuromodulators, collagen stimulators, and fillers. Understanding the unique traits and expectations of this particular population can lead to improved patient satisfaction, enhanced outcomes, and an overall positive experience.

Subcutaneous Application of a Gelatin/Hyaluronic Acid Hydrogel Induces the Production of Skin Extracellular Matrix

The development of injectable hydrogels with natural biopolymers such as gelatin (Ge) and hyaluronic acid (Ha) is widely performed due to their biocompatibility and biodegradability. The combination of both polymers crosslinked with N-Ethyl-N'-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) can be used as an innovative dermal filler that stimulates fibroblast activity and increases skin elasticity and tightness. Thus, crosslinked Ge/Ha hydrogels with different concentrations of EDC were administered subcutaneously to test their efficacy in young and old rats. At higher EDC concentrations, the viscosity decreases while the particle size of the hydrogels increases. At all concentrations of EDC, amino and carboxyl groups are present. The histological analysis shows an acute inflammatory response, which disappears seven days after application. At one and three months post-treatment, no remains of the hydrogels are found, and the number of fibroblasts increases in all groups in comparison with the control. In addition, the elastic modulus of the skin increases after three months of treatment. Because EDC-crosslinked Ge/Ha hydrogels are biocompatible and induce increased skin tension, fibroblast proliferation, and de novo extracellular matrix production, we propose their use as a treatment to attenuate wrinkles and expression lines.

The histologic reaction and permanence of hyaluronic acid gel, calcium hydroxylapatite microspheres, and extracellular matrix bio gel

BACKGROUND

The filling materials on the beauty market can be classified into three types: natural biological materials, synthetic polymer materials, and composites containing bioactive substances. However, comparative experimental data is lacking to compare their biological responses and permanence.

AIMS

The main object of this study was to evaluate the biological response of these three types of fillers to provide a theoretical basis for clinical application.

METHODS

Six-week-old female mice were injected subcutaneously with hyaluronic acid (HA) gel, calcium hydroxylapatite (CaHA) microspheres, and extracellular matrix (ECM) bio gel to observe the body reaction and permanence. At 1, 4, 8, and 16 weeks, the test sites were excised and analyzed by histopathology and proteomics.

RESULTS

Extracellular matrix had a minimal foreign body response. HA had a good volume effect at the early stage but the volume retention rate was lower than CaHA in the long term. CaHA could stimulate neo-collagen formation.

CONCLUSION

This study has proven the effectiveness and safety of these fillers and could provide clinical guidance for the plastic surgeon.

Objective Assessment of the Long-Term Volumizing Action of a Polycaprolactone-Based Filler

Background

The polycaprolactone-based filler, (PCL-1, Ellansé-S), forms part of the recently growing portfolio of biodegradable collagen-stimulating fillers. It is comprised of a suspension of 25-50 micron diameter microspheres of polycaprolactone (PCL) (30%) in a carboxymethyl cellulose (CMC) gel carrier (70%) and has gained popularity due to its long-term volumizing action.

Objective

This study outlines a retrospective case series of nine patients injected with the PCL-1, for volume augmentation in the mid-face. Objective volume calculations were performed with the Canfield Vectra 3D Imaging System at two time points post-implantation, with the objective of determining the longevity of the volumizing effect of the bio-stimulating substance.

Results

A clear increase in volume, between 50-150%, was found in all of the patients at two years, over and above the volume initially injected. All the patients were satisfied with the longevity of the results.

Discussion

The PCL-based filler is believed to afford immediate volume restoration due to the CMC gel component and a long-term action due to neo-collagenesis, induced by the PCL microspheres. The CMC gel is known to dissipate within 6-8 weeks, only to be replaced by new collagen induced by the PCL particles. Thus soft-tissue formation induced by the PCL particles, ultimately leads to a sustained volumizing effect.

Conclusion

The PCL-based filler is shown to have a sustained volumizing effects of at least 2 years duration with clear evidence of increase in volume over and above the volume injected, in all of the cases studied. This is indicative of significant neo-collagenesis induced by the PCL microspheres.

Aging of the Neck Decoded: New Insights for Minimally Invasive Treatments

BACKGROUND

Many signs of aging manifest in the neck region, including platysmal bands, excess skin, horizontal neck lines and decreasing contour of the neck. While the clinical signs of an aged neck are well-known, data determining the underlying aging process are limited.

OBJECTIVE

To decode aging of the neck.

MATERIALS AND METHODS

This prospective study investigated elasticity and firmness of skin, muscle activity and skin displacement upon muscular contraction in the neck in 77 young-, middle- and old-age individuals. Objective outcome measures, including 3-dimensional imaging, cutometry and surface electromyography, were utilized for all assessments.

RESULTS

Mean firmness of skin decreased significantly from young to old individuals (0.37 ± 0.13 mm, 0.30 ± 0.12 mm and 0.26 ± 0.12 mm in young, middle and old subjects, respectively; p < 0.001). Gross elasticity decreased significantly from 75.1 ± 13.0% in young subjects, to 64.53 ± 15.7% in middle-aged subjects and 55.79 ± 13.0% in old subjects (p < 0.001). The mean y-axis skin displacement increased from 2.48 ± 4.33 mm in young subjects, to 3.11 ± 4.49 mm in middle-aged subjects and 3.61 ± 5.38 mm in old subjects (p = 0.006). The mean signal-to-noise ratio decreased significantly from 16.74 ± 5.77 µV in young subjects, to 14.41 ± 4.86 µV in middle-aged subjects and to 12.23 ± 5.99 µV in old subjects (p < 0.001).

CONCLUSION

This study provides insights into the interplay between skin elasticity, muscular activity and the reflected movement of the skin of the neck. Appreciation of these age-related changes lays the fundament for aesthetic treatments in this delicate region.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

L-Lift Technique Using Poly-l-Lactic Acid: A Pilot Study

BACKGROUND

Minimally invasive procedures that prevent and delay the aging process can be an alternative to more invasive surgical procedures.

OBJECTIVE

To assess the efficacy and safety of L-Lift technique to improve skin firmness, facial global aesthetics, and the patient and investigator satisfaction.

METHODS

Prospective, open, single-center study. Thirty participants underwent 3 treatment sessions 1 month apart and were assessed 8, 16, and 24 weeks after first injections. Assessments included the Facial Laxity Rating Scale (FLRS), Global Aesthetic Improvement Scale (GAIS), objective measurement of skin elasticity, and the Skin Distension Test.

RESULTS

At Week 24, 60% of the patients had at least 1-class improvement in the FLRS for the middle face and 33% for the lower face. At Week 24, investigators considered that 90.0% of the patients improved according to the GAIS and 90.0% of the subjects considered they have improved. Skin elasticity (at Week 8 and at Week 16) and Skin Distension Test (at Week 24) assessments indicated improvement in skin firmness. Both patients and investigators were satisfied with the treatment at the study end.

CONCLUSION

The technique is safe and efficacious. It may be particularly suitable for patients presenting initial signs of facial skin laxity.

Effect of Hyaluronic Acid and Poly-L-Lactic Acid Dermal Fillers on Collagen Synthesis: An in vitro and in vivo Study

Purpose

Skin ageing is marked by structural and functional changes in epidermis and dermis, which result clinically in wrinkles, loss of elasticity, and rough-textured appearance. In this context, different dermal fillers have been used to overcome these negative effects associated with skin ageing, such as hyaluronic acid (HA) and poly-L-lactic acid (PLLA). Despite their low immunogenicity, these materials can cause an inflammatory reaction after application.

Materials and Methods

Considering high demand of HA and PLLA as filler material, this study aimed to evaluate their in vitro and in vivo effects. For the in vitro study, human dermal fibroblast cell cultures were supplemented with HA or PLLA for 24, 48, and 72 h. The following parameters were assayed: 1) cell proliferation, 2) cell viability, and 3) quantification of type I collagen by ELISA. For the in vivo study, HA or PLLA was injected in the dermis of Wistar rats and the tissues were collected after 15, 30, and 60 days for histologic evaluation and for quantification of type I collagen by Western blotting. The quantitative data were statistically analyzed using an ANOVA two-way. The significance level was set at 5%.

Results

At 72 h, high cell proliferation was observed for HA compared to control (p<0.05). Cultures exposed to PLLA exhibited a reduction in both cell proliferation and viability compared to control in all time points (p<0.05). Type I collagen expression was greater in cultures exposed to HA or PLLA compared to control (p<0.05). Histologic analysis showed the presence of multinucleated cells only in the PLLA group in all experimental time points. Western blotting analysis revealed high content of type I collagen in HA compared to PLLA (p<0.05).

Conclusion

The present study addresses a potentially unfavorable effect of dermal PLLA filler on the fibroblast phenotype, with possible clinical complications, unlike HA.

Rheologic properties of soft tissue fillers and implications for clinical use

BACKGROUND

The use of injectable soft-tissue fillers has become an essential tool in esthetic rejuvenation. Rheology, the study of flow of matter, helps to understand the function of these products.

AIMS

The purpose of this article is to review the rheologic properties of soft-tissue fillers currently available in the United States and to evaluate how these properties relate to clinical performance.

METHODS

This article explains basic rheologic terms and describes how rheologic properties of specific soft-tissue fillers affect filler performance.

RESULTS

The currently available soft-tissue fillers have unique rheologic and physicochemical properties that influence performance and cosmetic outcome. These properties determine that filler product is most appropriate based on degree of soft-tissue defect and anatomic location.

CONCLUSION

It is imperative for physicians to have an in-depth understanding of the rheologic properties of soft-tissue fillers in order to appropriately select and utilize these products for the desired cosmetic outcome.

Reconstitution of Injectable Poly-d,l-lactic Acid: Efficacy of Different Diluents and a New Accelerating Method

Injectable poly-d,l-lactic acid (PDLLA) is a new collagen-stimulating filler containing PDLLA microspheres and carboxymethyl cellulose. It is available as a lyophilized powder that must be reconstituted with a diluent before administration. The aims of this study were to investigate the efficacy of different diluents and a new accelerating “back-and-forth” method.

A prospective study comparing topic platelet-rich plasma vs. placebo on reducing superficial perioral wrinkles and restore dermal matrix

Introduction: The goal of our prospective study was to assess the efficacy of the topical Platelet-rich plasma on reducing superficial perioral wrinkles and restoring the dermal matrix. Materials and methods: 50 women with moderate to severe perioral wrinkles were treated on the perioral area by a single session of fractional CO2 laser skin resurfacing plus intradermal injection of prp. 25 patients (group 1) applied topically prp twice a day for 12 weeks as post laser treatment. 25 (group 2) applied gentamicin and betamethasone twice a day for the first 7 days and then hyaluronic acid gel for the following 12 weeks. Results: In group 1, moisture (p < 0.001), amount of collagen fiber (p < 0.001) skin elasticity (p < 0.001), PSAl (p < 0.001) and SSAl (p < 0.001) improved significantly. In group 2 all the parameters investigated improved but did not reach significant difference. Discussion: Our medical device with a plasma-like formulation is able to maintain prp active for a period of 7 days so patients are able to apply topically growth factors at home. Conclusions: Our prospective study proves that the use of topical prp reduces superficial perioral wrinkles and restore dermal matrix when used at home for 12 weeks.

Global Consensus Guidelines for the Injection of Diluted and Hyperdiluted Calcium Hydroxylapatite for Skin Tightening

BACKGROUND

Calcium hydroxylapatite (CaHA) is approved to correct moderate-to-severe wrinkles and folds and soft-tissue volume loss in the face and hands. More recently, subdermal injection using diluted CaHA has been used to improve skin laxity.

OBJECTIVE

To review evidence for the safe and effective use of diluted CaHA in the face and body and provide best practice recommendations.

METHODS

A global panel of expert aesthetic physicians convened to develop consensus-based guidelines for treating laxity and superficial wrinkles using diluted (ratio of 1:1) and hyperdiluted (≥1:2) CaHA.

RESULTS

Diluted and hyperdiluted CaHA stimulates targeted neocollagenesis in the injection area to improve laxity and skin quality in the mid- and lower face, neck, décolletage, upper arms, abdomen, upper legs, and buttocks. Treatment can be used as an adjunct to volume augmentation or combined with additional modalities for optimal results. Adverse events are related to the injection and include bruising, swelling, mild pain, and induration. In thinner and darker skin, too-superficial injections of less diluted CaHA can lead to more adverse events.

CONCLUSION

This report provides preliminary guidelines for the novel off-label use of CaHA for biostimulation in the face and body. Further trials will provide additional clarity regarding treatment paradigms for optimal outcomes.