The Paracrine Effect of Adipose-Derived Stem Cells Orchestrates Competition between Different Damaged Dermal Fibroblasts to Repair UVB-Induced Skin Aging

Effect of a New Hyaluronic Acid Hydrogel Dermal Filler Cross-Linked With Lysine Amino Acid for Skin Augmentation and Rejuvenation

BACKGROUND

Hyaluronic acid (HA) fillers are the most popular filler agents for skin rejuvenation. Although 1,4-butanediol diglycidyl ether is regarded as a relatively safe cross-linker, it still exhibits certain cytotoxicity.

OBJECTIVES

We presented here an amino acid-cross-linked HA (ACHA) which was obtained by an amidation reaction with lysine and HA. This study aimed to investigate ACHA's efficacy and safety for skin augmentation and rejuvenation.

METHODS

Rheology, compressive tests, and swelling experiments were conducted to investigate ACHA's mechanical and viscoelastic properties. The effects of ACHA on the human keratinocytes (HaCaT) cells and the human dermal fibroblast (HDF) were investigated by Transwell and wound healing assays. Its impacts on the epithelial thickness and collagen synthesis were further examined in a mouse experimental model. We recruited 50 patients with moderate to severe nasolabial folds (NLFs). The patients were randomly allocated to receive ACHA or Restylane injections. The resulting retention rates of HA and the Wrinkle Severity Rating Scale and Global Aesthetic Improvement Scale outcomes were evaluated and compared.

RESULTS

ACHA exhibited good viscoelasticity. It not only promoted migration and proliferation of HaCat and HDF and secretion of various growth factors but also increased skin thickness and promoted the generation of collagen. Patients who received ACHA had more residual volume 12 months after treatment. ACHA exhibited a promising augmentation effect in NLF correction with few adverse reactions.

CONCLUSIONS

ACHA has shown promise as a biomaterial with excellent biocompatibility and viscoelastic characteristics in both research and the clinic.See the abstract translated into Hindi, Portuguese, Korean, German, Italian, Arabic, Chinese, and Taiwanese online here: https://doi.org/10.1093/asj/sjad169.

LEVEL OF EVIDENCE: 2

Recent advances in exosomal non-coding RNA-based therapeutic approaches for photoaging

BACKGROUND

Photoaging is a degenerative biological process that affects the quality of life. It is caused by environmental factors including ultraviolet radiation (UVR), deep skin burns, smoking, active oxygen, chemical substances, and trauma. Among them, UVR plays a vital role in the aging process.

AIM

With the continuous development of modern medicine, clinical researchers have investigated novel approaches to treat aging. In particular, mesenchymal stem cells (MSCs), non-coding RNAs are involved in various physiological processes have broad clinical application as they have the advantages of convenient samples, abundant sources, and avoidable ethical issues.

METHODS

This article reviews research progress on five types of stem cell, exosomes, non-coding RNA in the context of photoaging treatment: adipose-derived stem cell, human umbilical cord MSCs, epidermal progenitor cells, keratinocyte stem cells, and hair follicle stem cells (HFSCs). It also includes stem cell related exosomes and their non-coding RNA research.

RESULTS

The results have clinical guiding significance for prevention and control of the onset and development of photoaging. It is found that stem cells secrete cytokines, cell growth factors, non-coding RNA, exosomes and proteins to repair aging skin tissues and achieve skin rejuvenation. In particular, stem cell exosomes and non-coding RNA are found to have significant research potential, as they possess the benefits of their source cells without the disadvantages which include immune rejection and granuloma formation.

Peelable Microneedle Patches Deliver Fibroblast Growth Factors to Repair Skin Photoaging Damage

Rationale: UV light deeply penetrates the dermis, leading to inflammation and cell death with prolonged exposure. This is a major contributor to skin photoaging. In the pharmaceutical field, fibroblast growth factors (FGFs) have gained popularity for enhancing skin quality as they facilitate tissue remodeling and re-epithelization. Nonetheless, their effectiveness is significantly hindered by limited absorption. Methods: We have successfully created a dissolving microneedle (MN) patch that contains hyaluronic acid (HA) loaded with FGF-2 and FGF-21. This patch aims to improve the therapeutic efficiency of these growth factors while providing a simple administration method. We determined the performance of this patch in an animal model of skin photoaging. Results: The FGF-2/FGF-21-loaded MN (FGF-2/FGF-21 MN) patch demonstrated a consistent structure and suitable mechanical properties, allowing for easy insertion and penetration into mouse skin. Within 10 minutes of application, the patch released approximately 38.50 ± 13.38% of the loaded drug. Notably, the FGF-2/FGF-21 MNs exhibited significant improvements in UV-induced acute skin inflammation and reduced mouse skin wrinkles within a span of two weeks. Furthermore, the positive effects continued to enhance over a four-week treatment period. Conclusion: The proposed HA-based peelable MN patch provides an efficient approach for transdermal drug delivery, providing a promising method for improved therapeutic outcomes.

Poly-D,L-Lactic Acid Filler Increases Extracellular Matrix by Modulating Macrophages and Adipose-Derived Stem Cells in Aged Animal Skin

Poly-D,L-lactic acid (PDLLA) filler corrects soft tissue volume loss by increasing collagen synthesis in the dermis; however, the mechanism is not fully understood. Adipose-derived stem cells (ASCs) are known to attenuate the decrease in fibroblast collagen synthesis that occurs during aging, and nuclear factor (erythroid-derived 2)-like-2 factor (NRF2) increases ASCs survival by inducing M2 macrophage polarization and IL-10 expression. We evaluated the ability of PDLLA to induce collagen synthesis in fibroblasts by modulating macrophages and ASCs in a H₂O₂-induced cellular senescence model and aged animal skin. PDLLA increased M2 polarization and NRF2 and IL-10 expression in senescence-induced macrophages. Conditioned media from senescent macrophages treated with PDLLA (PDLLA-CM_MΦ) reduced senescence and increased proliferation and expression of transforming growth factor-β (TGF-β) and fibroblast growth factor (FGF) 2 in senescence-induced ASCs. Conditioned media from senescent ASCs treated with PDLLA-CM_MΦ (PDLLA-CM_ASCs) increased the expression of collagen 1a1 and collagen 3a1 and reduced the expression of NF-κB and MMP2/3/9 in senescence-induced fibroblasts. Injection of PDLLA in aged animal skin resulted in increased expression of NRF2, IL-10, collagen 1a1, and collagen 3a1 and increased ASCs proliferation in aged animal skin. These results suggest that PDLLA increases collagen synthesis by modulating macrophages to increase NRF2 expression, which stimulates ASCs proliferation and secretion of TGF-β and FGF2. This leads to increased collagen synthesis, which can attenuate aging-induced soft tissue volume loss.

miR-1246-overexpressing exosomes suppress UVB-induced photoaging via regulation of TGF-β/Smad and attenuation of MAPK/AP-1 pathway

Stem cell therapy is widely employed for the treatment of skin diseases, especially in skin rejuvenation. Exosomes derived from stem cells have been demonstrated to possess anti-photoaging effects; however, the precise components within exosomes that are responsible for this effect remain unknown. Previously, miR-1246 was found to be one of the most abundant nucleic acids in adipose-derived stem cells (ADSCs)-derived exosomes. This study examined whether miR-1246 was the major therapeutic agent employed by ADSCs to protect against UVB-induced photoaging. Lentivirus infection was used to obtain miR-1246-overexpressing ADSCs and exosomes. We then determined the anti-photoaging effects of miR-1246-overexpressing exosomes (OE-EX) on both UVB-irradiated human skin fibroblasts (HSFs) and Kunming mice. The results showed that OE-EX could significantly decrease MMP-1 by inhibiting the MAPK/AP-1 signaling pathway. Meanwhile, OE-EX markedly increased procollagen type I secretion by activating the TGF-β/Smad pathway. OE-EX also exhibited an anti-inflammatory effect by preventing the UVB-induced degradation of IκB-α and NF-κB overexpression. Animal experiments demonstrated that OE-EX could reduce UVB-induced wrinkle formation, epidermis thickening, and the loss of collagen fibers reduction in Kunming mice. The combined results suggested that miR-1246 is the key component within ADSCs-derived exosomes that protects against UVB-induced skin photoaging.

Direct three-dimensional printed egg white hydrogel wound dressing promotes wound healing with hitching adipose stem cells

Current wound dressing based on hydrogel offers a promising way to accelerate the healing process, yet great challenges remain in the development of a highly integrated and efficient platform with the combination of therapeutic biomolecules and stem cells. Herein, a natural hydrogel wound dressing from egg white can be conveniently obtained by feasible physical crosslinking, the prepared hydrogel dressing features interconnected microporous channels, direct 3D printing, cytocompatibility, and intrinsic biomolecules to advance cell behavior. The 3D printed egg white hydrogels promote the adhesion and proliferation of adipose-derived stem cells (ASCs) without obvious cytotoxicity. In addition, this integrated hydrogel platform accompanied with adipose-derived stem cells accelerates wound healing through the enhancement of fibroblast proliferation, angiogenesis, and collagen rearrangement in the wound bed. The egg white hydrogel provides an effective wound caring product possessing low cost, easy availability along with ready manufacturing, and advanced therapeutic effect, which may be extended for the management of chronic or other complicated wounds.

Association Between Fat Graft Retention and Blood Flow in Localized Scleroderma Patients: A Pilot Study

Background

Microcirculation plays a vital role in scleroderma physiopathology and the mechanism of fat survival.

Objective

This study aims to assess the blood perfusion change after fat grafting and evaluate the relationship between blood perfusion and fat graft retention in patients with localized scleroderma (LS).

Methods

A pilot study was conducted in patients with LS receiving autologous fat grafting (AFG). Fat graft retention measured by magnetic resonance imaging (MRI) analysis and blood flow perfusion measured by laser speckle contrast imaging 6 months postoperatively were noted. PUMC Localized Scleroderma Facial Aesthetic Index was used to assess the improvement of facial aesthetic impairment.

Results

The fat retention at the 6-month follow-up was 34.56 ± 11.89 percent. At the 6th month of follow-up, the relative blood perfusion at the lesion area was 115.08 ± 14.39 PU, significantly higher than 100.42 ± 10.62 PU at the pre-operation (p = 0.010). The blood perfusion at follow-up increased by an average of 1.15 ± 0.14 times before the operation. No association between the increase in the blood flow perfusions and fat graft retention was found (r = −0.082, p = 0.811).

Conclusion

Local blood perfusion in the lesion area relatively increased after AFG, but no direct relationship was found between fat retention and increased blood supply.

A Novel Approach for Skin Regeneration by a Potent Bioactive Placental-Loaded Microneedle Patch: Comparative Study of Deer, Goat, and Porcine Placentas

The aims of this study were to investigate the skin regeneration potential of bioactive placenta (deer placenta (DP), goat placenta (GP), and porcine placenta (PP)) and fabricate bioactive extract-loaded dissolving microneedles (DMNs) as a dermal delivery approach. The placentas were water-extracted, and the active compounds were evaluated. Bioactivity studies were performed in dermal fibroblasts and keratinocytes. DMNs were fabricated to deliver the potent bioactive placenta extract into the skin. All placental extracts expressed high amounts of protein, growth factors (EGF, FGF, IGF-1 and TGF-β1), and amino acids. These extracts were not toxic to the skin cells, while the proliferation of fibroblast cells significantly increased in a time-dependent manner. GP extract that exhibited the maximum proliferation, migration, and regeneration effect on fibroblast cells was loaded into DMN patch. The suitable physical properties of DMNs led to increased skin permeation and deposition of bioactive macromolecules. Moreover, GP extract-loaded DMNs showed minimal invasiveness to the skin and were safe for application to human skin. In conclusion, placental extracts act as potent bioactive compounds for skin cells, and the highest bioactive potential of GP-loaded DMNs might be a novel approach to regenerate the skin.

Research update of adipose tissue-based therapies in regenerative dermatology

Mesenchymal stromal/stem cells (MSCs) have a spontaneous propensity to support tissue homeostasis and regeneration. Among the several sources of MSCs, adipose-derived tissue stem cells (ADSCs) have received major interest due to the higher mesenchymal stem cells concentration, ease, and safety of access. However, since a significant part of the natural capacity of ADSCs to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines, lipids, and extracellular matrix components, several studies focused on cell-free strategies. Furthermore, adipose cell-free derivatives are becoming more attractive especially for non-volumizing purposes, such as most dermatological conditions. However, when keratinocytes, fibroblasts, melanocytes, adipocytes, and hair follicle cells might not be locally sourced, graft of materials containing concentrated ADSCs is preferred. The usage of extracellular elements of adipose tissue aims to promote a self-autonomous regenerative microenvironment in the receiving area restoring physiological homeostasis. Hence, ADSCs or their paracrine activity are currently being studied in several dermatological settings including wound healing, skin fibrosis, burn, and aging.The present work analyzing both preclinical and clinical experiences gives an overview of the efficacy of adipose tissue-derivatives like autologous fat, the stromal vascular fraction (SVF), purified ADSCs, secretome and extracellular matrix graft in the field of regenerative medicine for the skin.

Adipose Stem Cell-Based Treatments for Wound Healing

Wound healing is one of the most complex physiological regulation mechanisms of the human body. Stem cell technology has had a significant impact on regenerative medicine. Adipose stem cells (ASCs) have many advantages, including their ease of harvesting and high yield, rich content of cell components and cytokines, and strong practicability. They have rapidly become a favored tool in regenerative medicine. Here, we summarize the mechanism and clinical therapeutic potential of ASCs in wound repair.

Anti-aging effects of fetal dermal mesenchymal stem cells in a D-galactose-induced aging model of adult dermal fibroblasts

The main characteristic of skin aging is the change in the composition of the dermis, mainly resulting from fibroblast senescence. Mesenchymal stem cells derived from fetal dermis are defined as fetal dermal mesenchymal stem cells; they reportedly exert wound healing effects on the skin and regulate keloid fibroblast proliferation. D-Galactose is widely used in animal aging models. In this study, we confirmed that D-galactose inhibits adult dermal fibroblast proliferation, and the inhibitory effect gradually increased with increasing concentration. Finally, we chose a concentration of 40 g/L D-galactose to induce adult dermal fibroblast senescence. D-Galactose increased the intensity of senescence-associated β-galactosidase staining and the levels of reactive oxygen species in adult dermal fibroblasts. Furthermore, D-galactose increased the mRNA expression of p16, p21, and p53. The fetal dermal mesenchymal stem cell-conditioned medium improved the above-mentioned effects. Overall, fetal dermal mesenchymal stem cells exerted anti-aging effects against adult dermal fibroblasts induced by D-galactose via paracrine functions.