Long-chain polynucleotide filler for skin rejuvenation: efficacy and complications in five patients

Investigating the Mechanisms of Intradermal Injection for Easier "Skin Booster" Treatment: A Fluid Mechanics Approach to Determine Optimal Delivery Method

Background

The use of "skin boosters" for rejuvenating aged skin is widely used. However, the accurate injection of the skin booster into the dermal layer remains a challenge due to the density of the dermis. The purpose of this study was to investigate the optimal mechanical variables of delivery that enabled correct targeting of the product to the dermis for optimal results.

Methods

We investigated the impact of mechanical variables (syringe diameter, needle diameter and length, and viscosity of the skin booster) on the force required for intradermal injection in porcine skin. The correlation between these variables and the injection force was examined as well.

Results

The results show that smaller syringe diameters, larger needle diameters, shorter needle lengths, and lower viscosity of the skin boosters reduce the injection force needed for intradermal injections.

Conclusions

During the administration of skin booster injections, clinicians should take into account optimal conditions that facilitate intradermal injections, thus maximizing rejuvenating outcomes. Furthermore, manufacturers of skin boosters should formulate the products with decreased viscosity and provide the product in conjunction with appropriate needles and syringes, designed to optimize ease of injection.

High-resolution 3-D scanning electron microscopy (SEM) images of DOTTM polynucleotides (PN): Unique scaffold characteristics and potential applications in biomedicine

INTRODUCTION

Polynucleotides (PN) are becoming more prominent in aesthetic medicine. However, the structural characteristics of PN have not been published and PN from different companies may have different structural characteristics. This study aimed to elucidate the structural attributes of DOT™ PN and distinguish differences with polydeoxyribonucleotides (PDRN) using high-resolution scanning electron microscopy (SEM) imaging.

MATERIALS AND METHODS

DOT™ PN was examined using a Quanta 3-D field emission gun (FEG) Scanning Electron Microscope (SEM). Sample preparation involved cryogenic cooling, cleavage, etching, and metal coating to facilitate high-resolution imaging. Cryo-FIB/SEM techniques were employed for in-depth structural analysis.

RESULTS

PDRN exhibited an amorphous structure without distinct features. In contrast, DOT™ PN displayed well-defined polyhedral shapes with smooth, uniformly thick walls. These cells were empty, with diameters ranging from 3 to 8 micrometers, forming a seamless tessellation pattern.

DISCUSSION

DOT™ PN's distinct geometric tessellation design conforms to the principles of biotensegrity, providing both structural reinforcement and integrity. The presence of delicate partitions and vacant compartments hints at possible uses in the field of pharmaceutical delivery systems. Within the realms of beauty enhancement and regenerative medicine, DOT™ PN's capacity to bolster cell growth and tissue mending could potentially transform approaches to rejuvenation treatments. Its adaptability becomes apparent when considering its contributions to drug administration and surgical procedures.

CONCLUSION

This study unveils the intricate structural scaffold features of DOT™ PN for the first time, setting it apart from PDRN and inspiring innovation in biomedicine and materials science. DOT™ PN's unique attributes open doors to potential applications across healthcare and beyond.

Skin boosters: Definitions and varied classifications

BACKGROUND

The concept of "skin boosters" has evolved, marking a shift from traditional uses of hyaluronic acid (HA) fillers primarily for augmenting skin volume to a more diverse application aimed at improving dermal conditions. Restylane Vital and other HA fillers have been repurposed to combat skin aging and wrinkles by delivering HA directly to the dermis.

OBJECTIVES

This review aims to define the term "skin booster" and to discuss the various components that constitute skin boosters. It seeks to provide a comprehensive overview of the different ingredients used in skin boosters, their roles, and their impact on enhancing dermal conditions.

METHODS

A comprehensive review was conducted, focusing on representative skin booster ingredients. The approach involved analyzing the different elements used in skin boosters and their specific roles in enhancing dermal improvement.

RESULTS

The findings indicate that skin boosters, encompassing a range of ingredients, are effective in improving the condition of the skin's dermis. The review identifies key ingredients in skin boosters and their specific benefits, including hydration, elasticity improvement, and wrinkle reduction.

CONCLUSIONS

Skin boosters represent a significant development in dermatological treatments, offering diverse benefits beyond traditional HA fillers. This review provides valuable insights into the constituents of skin boosters and their effectiveness, aiding readers in making informed decisions about these treatments. The potential of skin boosters in dermatological practice is considerable, warranting further research and application.

Full-thickness skin rejuvenation by a novel dual-length microneedle radiofrequency device: A proof-of-concept study using human skin

BACKGROUND

A novel dual-length microneedle radiofrequency (DLMR) device has been developed to achieve full-thickness skin rejuvenation by stimulating the papillary and reticular dermis simultaneously. This device's dual-level targeting concept need to be validated on human skin, although its clinical efficacy has been demonstrated in a previous study.

OBJECTIVES

This study evaluated the dual-depth targeting capability and the ability to induce rejuvenation in each layer of vertical skin anatomy, that is, the epidermis, papillary dermis, and reticular dermis, using full-thickness human facial skin samples.

METHODS

Human facial skin samples were obtained from 13 Asian patients who had facelift surgery. To validate the dual-depth targeting concept, DMLR-treated skin samples were analyzed using a digital microscope, thermal imaging, and hematoloxylin and eosin (H&E) staining immediately after DLMR application. On samples stained with H&E, Masson's tricrome, and Verhoeff-Van Gieson, histological observation and morphometric analysis were performed. Total collagen assay (TCA) and quantitative real-time polymerase chain reaction (qPCR) were used to assess changes in total collagen content and mRNA expression levels of collagen types I/III and vimentin, respectively.

RESULTS

The DLMR device successfully induced thermal stimulation in the papillary and reticular dermis. The thickness, stacks, and dermal-epidermal junction convolution of the epidermis treated with DLMR were significantly increased. Collagen bundles in the dermis treated with DLMR exhibited a notable increase in thickness, density, and horizontal alignment. Dermal collagen levels were significantly higher in the morphometric and TCA data, as well as in the qPCR data for dermal matrix proteins.

CONCLUSIONS

Our DLMR device independently and precisely targeted the papillary and reticular dermis, and it appears to be an effective modality for implementing full-thickness rejuvenation.

Polynucleotides Suppress Inflammation and Stimulate Matrix Synthesis in an In Vitro Cell-Based Osteoarthritis Model

Osteoarthritis (OA) is characterized by degeneration of the joint cartilage, inflammation, and a change in the chondrocyte phenotype. Inflammation also promotes cell hypertrophy in human articular chondrocytes (HC-a) by activating the NF-κB pathway. Chondrocyte hypertrophy and inflammation promote extracellular matrix degradation (ECM). Chondrocytes depend on Smad signaling to control and regulate cell hypertrophy as well as to maintain the ECM. The involvement of these two pathways is crucial for preserving the homeostasis of articular cartilage. In recent years, Polynucleotides Highly Purified Technology (PN-HPT) has emerged as a promising area of research for the treatment of OA. PN-HPT involves the use of polynucleotide-based agents with controlled natural origins and high purification levels. In this study, we focused on evaluating the efficacy of a specific polynucleotide sodium agent, known as CONJURAN, which is derived from fish sperm. Polynucleotides (PN), which are physiologically present in the matrix and function as water-soluble nucleic acids with a gel-like property, have been used to treat patients with OA. However, the specific mechanisms underlying the effect remain unclear. Therefore, we investigated the effect of PN in an OA cell model in which HC-a cells were stimulated with interleukin-1β (IL-1β) with or without PN treatment. The CCK-8 assay was used to assess the cytotoxic effects of PN. Furthermore, the enzyme-linked immunosorbent assay was utilized to detect MMP13 levels, and the nitric oxide assay was utilized to determine the effect of PN on inflammation. The anti-inflammatory effects of PN and related mechanisms were investigated using quantitative PCR, Western blot analysis, and immunofluorescence to examine and analyze relative markers. PN inhibited IL-1β induced destruction of genes and proteins by downregulating the expression of MMP3, MMP13, iNOS, and COX-2 while increasing the expression of aggrecan (ACAN) and collagen II (COL2A1). This study demonstrates, for the first time, that PN exerted anti-inflammatory effects by partially inhibiting the NF-κB pathway and increasing the Smad2/3 pathway. Based on our findings, PN can potentially serve as a treatment for OA.

Skin aging from mechanisms to interventions: focusing on dermal aging

Skin aging is a multifaceted process that involves intrinsic and extrinsic mechanisms that lead to various structural and physiological changes in the skin. Intrinsic aging is associated with programmed aging and cellular senescence, which are caused by endogenous oxidative stress and cellular damage. Extrinsic aging is the result of environmental factors, such as ultraviolet (UV) radiation and pollution, and leads to the production of reactive oxygen species, ultimately causing DNA damage and cellular dysfunction. In aged skin, senescent cells accumulate and contribute to the degradation of the extracellular matrix, which further contributes to the aging process. To combat the symptoms of aging, various topical agents and clinical procedures such as chemical peels, injectables, and energy-based devices have been developed. These procedures address different symptoms of aging, but to devise an effective anti-aging treatment protocol, it is essential to thoroughly understand the mechanisms of skin aging. This review provides an overview of the mechanisms of skin aging and their significance in the development of anti-aging treatments.

Poly-D,L-Lactic Acid Stimulates Angiogenesis and Collagen Synthesis in Aged Animal Skin

Angiogenesis promotes rejuvenation in multiple organs, including the skin. Heat shock protein 90 (HSP90), hypoxia-inducible factor-1 alpha (HIF-1α), and vascular endothelial growth factor (VEGF) are proangiogenic factors that stimulate the activities of phosphoinositide 3-kinase (PI3K), protein kinase B (AKT), and extracellular signal-regulated kinase 1/2 (ERK1/2). Poly-D,L-lactic acid (PDLLA), polynucleotide (PN), and calcium hydroxyapatite (CaHA) are dermal fillers that stimulate the synthesis of dermal collagen. However, it is not yet known whether these compounds promote angiogenesis, which leads to skin rejuvenation. Here, we evaluated whether PDLLA, PN, and CaHA stimulate angiogenesis and skin rejuvenation using H₂O₂-treated senescent macrophages and endothelial cells as an in vitro model for skin aging, and we used young and aged C57BL/6 mice as an in vivo model. Angiogenesis was evaluated via endothelial cell migration length, proliferation, and tube formation after conditioned media (CM) from senescent macrophages was treated with PDLLA, PN, or CaHA. Western blot showed decreased expression levels of HSP90, HIF-1α, and VEGF in senescent macrophages, but higher expression levels of these factors were found after treatment with PDLLA, PN, or CaHA. In addition, after exposure to CM from senescent macrophages treated with PDLLA, PN, or CaHA, senescent endothelial cells expressed higher levels of VEGF receptor 2 (VEGFR2), PI3K, phosphorylated AKT (pAKT), and phosphorylated ERK1/2 (pERK1/2) and demonstrated greater capacities for cell migration, cell proliferation, and tube formation. Based on the levels of 4-hydroxy-2-nonenal, the oxidative stress level was lower in the skin of aged mice injected with PDLLA, PN, or CaHA, while the tumor growth factor (TGF)-β1, TGF-β2, and TGF-β3 expression levels; the density of collagen fibers; and the skin elasticity were higher in the skin of aged mice injected with PDLLA, PN, or CaHA. These effects were greater in PDLLA than in PN or CaHA. In conclusion, our results are consistent with the hypothesis that PDLLA stimulates angiogenesis, leading to the rejuvenation of aged skin. Our study is the first to show that PDLLA, PN, or CaHA can result in angiogenesis in the aged skin, possibly by increasing the levels of HSP90, HIF-1α, and VEGF and increasing collagen synthesis.

Effects of Polynucleotide Dermal Filler in the Correction of Crow's Feet Using an Antera Three-Dimensional Camera

BACKGROUND

Dermal fillers are gaining interest for tissue enlargement and skin improvement. Among them, polynucleotides have demonstrated multiple skin beneficial effects. The effects of polynucleotide fillers were objectively evaluated using an Antera 3D camera, subjectively evaluated by participants and investigators.

METHODS

Thirty subjects with crow's feet were enrolled in the study. The subjects received polynucleotide filler for crow's feet. Crow's feet grading score (CFGS), global esthetic improvement scale (GAIS), and Antera 3D imaging results were evaluated.

RESULTS

Twenty-eight subjects (93.3%) completed the study. An improvement in CFGS compared with that at baseline (p < 0.001) was observed 18 weeks after the first injection of polynucleotides. Additionally, at the final visit, there were improvements in wrinkle, texture, pore, depression, and Hb values compared with those at baseline (p < 0.05). However, no significant difference in melanin level was detected between the initial and final visits.

CONCLUSIONS

Improvements in wrinkles, pores, texture, depression, and Hb level after polynucleotide filler injection were verified by objective and subjective evaluations. To the best of our knowledge, this is the first report on the objective evaluation of polynucleotide fillers in crow's feet using the Antera 3D camera.

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 .

Comparative Evaluation of Safety and Efficacy of a Novel Hyaluronic Acid-polynucleotide/Poly-L-lactic Acid Composite Dermal Filler

BACKGROUND

Poly-L-lactic acid (PLLA) is widely used in tissue engineering. The natural polymer hyaluronic acid (HA) shows excellent biocompatibility and affects cell signaling, proliferation, and differentiation. In addition, a polynucleotide (PN) induces cell growth of human skin fibroblasts and osteoblasts.

OBJECTIVE

In this study, we evaluated the properties, safety, and efficacy of a novel composite filler consisting of cross-linked HA with PN in combination with monodisperse PLLA microspheres manufactured using Inventage Lab Precision Particle Fabrication method.

MATERIALS AND METHODS

The composition of the filler and characteristics of the microspheres were examined via scanning electron microscopy, particle size analysis, gel permeation chromatography, and rheology and osmolality measurement. Additionally, safety and efficacy of HA-PN/PLLA composite filler were conducted in in vitro and in vivo.

RESULTS

Analysis of PLLA microspheres revealed spherical surfaces and a narrower particle size distribution than that in PLLA filler. HA-PN/PLLA composite filler had higher viscosity and elasticity values and similar osmolality as compared to those of HA and PN fillers. The nontoxicity in in vitro and in vivo tests reflected that the composite filler may be safe for human use. In addition, the composite filler maintained a more stable volume than did HA filler for 24 weeks after administration in HWY/Slc hairless rats. Furthermore, the results support the effect of HA-PN/PLLA in restoring skin structure.

CONCLUSION

Altogether, these data suggest that the novel composite filler might be a safe and effective option in terms of tissue integration, clinical management during delivery and high esthetic durability.

LEVEL OF EVIDENCE III

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 .

Consensus report on the use of PN-HPT™ (polynucleotides highly purified technology) in aesthetic medicine

Background

Injective procedures using polynucleotides‐based products to promote dermal rejuvenation and revitalization are steadily evolving, yet no structured protocols are available that discuss and provide guidance in aesthetic treatments with highly purified polynucleotides. The goal of this document was to provide consensus‐based recommendations for the safe and effective use of Polynucleotides Highly Purified Technology™ (PN‐HPT™) devices for skin rejuvenation.

Patients/Methods

A team of eight experts with extensive experience in treatments for skin rejuvenation and revitalization integrated the best available evidence and clinical judgment and devised a series of practical guidance to support dermatologists, plastic surgeons, and aesthetic physician in the use of PN‐HPT™ products, alone and in combination, in aesthetic medicine.

Results

For most items, the expert group achieved a majority consensus. “Recommendations” (consensus >80%) were reached for the face, periocular area, décolleté and neck, hands, scalp, and stretch marks. Recommendations include details of techniques, information on dosage, volumes to be injected, and the ideal number of required treatment sessions, as well as time intervals between them for different areas of face and body. A lower agreement level of 60% was reached on but one item related to the initial treatment cycle for the face, leading to a “Consensus statement” for that area instead of a full “Recommendation.”

Conclusion

The expert consensus illustrates the value of natural‐origin, highly purified polynucleotides (PN‐HPT™) as biostimulatory booster strategy for skin priming and revitalization of face and body and provides a detailed guide for the use.

Comparison of the effects of polynucleotide and hyaluronic acid fillers on periocular rejuvenation: a randomized, double-blind, split-face trial

Background: Filler injection has become an extremely popular method for facial skin rejuvenation, including the periorbital area. In the recent years, new polynucleotide (PN)-containing filler products have been used for esthetic purposes.Aim: We aimed to investigate the efficacy and safety of PN filler injection in the periorbital area.Patients/methods: A total of 27 subjects were enrolled in this randomized, pair-matched, and active-controlled study. Each subject received filler injections thrice with two-week intervals, with a PN filler injection on one side and a non-crosslinked hyaluronic acid (HA) filler injection on the contralateral side of the periorbital area.Results: Improvements in the visual analog scale and global esthetic improvement scale scores were not significantly different between the PN and HA groups. The improvement rates of skin elasticity and hydration decreased over time in both groups, with the PN group showing a higher improvement rate. The improvement rates of roughness and pore volume were higher in the PN group than in the HA group. The improvement rate of dermal density was not significantly different between the groups. No serious adverse events were reported.Conclusion: The PN filler injection is effective and safe for periorbital rejuvenation.

Comparative Evaluation of the Effectiveness of Novel Hyaluronic Acid-Polynucleotide Complex Dermal Filler

HA (Hyaluronic acid) filler, the most commonly used dermal filler, causes several side effects. HA-PN (Hyaluronic acid-Polynucleotide), a new composite filler, has excellent biocompatibility and induces tissue regeneration. In this study, we compare the efficacies and safety profiles of these fillers. The characteristics of HA and HA-PN fillers were compared using scanning electron microscopy and rheometry. No morphological difference was noted between the fillers. However, the latter had higher viscosity and elasticity values. The HA-PN filler induced higher cell migration than the HA filler in a wound healing assay. It was also found to stimulate better collagen synthesis in human and mouse fibroblasts. The HA and HA-PN fillers were injected into SKH1 hairless mice to determine changes in their volume for up to 24 weeks. Increased cell migration and collagen synthesis were observed in mice injected with the HA-PN complex filler. Although the safety and durability of the HA and HA-PN fillers were similar, the latter induced a lower transient receptor potential vanilloid 4 expression and caused less stimulation upon injection. In conclusion, HA-PN complex fillers can stimulate fibroblast growth and facilitate volume growth and skin regeneration.

The efficacy and safety of BM-PHA for the correction of nasolabial folds: a multicenter, randomized, double-blind, split-face clinical trial

Background: Multiple types of fillers have been developed for soft tissue augmentation.Objective: We investigated the efficacy and safety of the novel filler BM-PHA.Methods: In this multicenter, randomized, split-face study, 91 participants received injections of BM-PHA and Restylane Perlane (PER) into the nasolabial folds. Efficacy was determined by the improvements in the Wrinkle Severity Rating Score (WSRS) and Global Esthetic Improvement Scale (GAIS), and safety by adverse events, laboratory tests, and a check of vital signs.Results: WSRS scores assessed by independent evaluators at Week 24, the primary efficacy measure, showed no significant difference between the two treatments. The treatments also showed no significant differences in WSRS scores assessed by the evaluators at Week 8 and WSRS and GAIS scores assessed by the treating investigators and participants at Weeks 8 and 24. The proportion of nasolabial folds whose WSRS scores improved by at least one grade at Week 24 was similar between the treatments. Only minor local side effects were reported without sequelae.Conclusion: BM-PHA was not inferior to PER in the treatment of moderate to severe nasolabial folds and may be an appropriate alternative product for their improvement. Further studies are needed to confirm the long-term safety of BM-PHA.

Treatments of Infra-Orbital Dark Circles by Various Etiologies

Dark circles refer to visible darkness of the infra-orbital areas. Dark circles are a cosmetic concern for many individuals, although not a medical concern. Moreover, clear definitions and possible causes of dark circles have not been elucidated. This study reviews the possible causes and treatment options for dark circles based on a review of the medical literature and the authors' clinical experience. Potential factors that contribute to dark circles include excessive pigmentation, shadowing due to tear troughs and infra-orbital fat herniation, shadowing due to infraorbital laxity and wrinkles, and thin, translucent skin overlying the orbicularis oculi muscle. Given the different possible causes for dark circles, therapeutic modalities must be individualized for each patient. Because various factors cause dark circles, it is useful to identify the underlying causes in order to select the appropriate treatment.