Dermal Collagen Synthesis Research Articles

Improvement in the Youthfulness of Facial Skin after a Single Treatment with Platelet Rich Plasma

Objective: Platelet rich plasma (PRP) is an autologous substance widely used to stimulate dermal collagen synthesis. This study aimed to investigate the efficacy of a single PRP treatment for facial rejuvenation. Materials and Methods: This study was conducted at the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from August 2020 to March 2021. Enrolled patients underwent a single intradermal injection treatment of 0.1 mL PRP at 30 locations on the face. Outcomes were assessed at 1, 2, and 4 weeks post-intervention using the patient-perceived age visual analog scale (VAS), FACE-Q assessment, and elasticity index (EI) with a Cutometer. Results: Forty Thai patients with an average age of 36.4 years, Fitzpatrick skin type 3-4 were enrolled. The mean Patient-perceived Age VAS significantly decreased one month after treatment (-2.71±2.42, p<0.001). FACE-Q satisfaction with facial skin was 74.29±14.49, and satisfaction with the outcome was 73.41±16.26 (scale 0-100). The PRP significantly affected skin EI, with the peak improvement observed at 1-2 weeks post-injection, predominantly at the cheek, crow’s feet, and perioral area (all p<0.05). All patients had an overall improvement in satisfaction scores throughout the study. Conclusion: A single treatment of PRP injection resulted in overall satisfaction in facial skin rejuvenation as measured by patient-perceived age VAS and FACE-Q assessment. The PRP showed positive outcomes in EI with peak performance at 1-2 weeks post-treatment.

Augmenting dermal collagen synthesis through hyaluronic acid-based microneedle-mediated delivery of poly(l-lactic acid) microspheres

Poly(L-lactic acid) (PLLA) can stimulate collagen synthesis through a foreign body response. However, inappropriate injection techniques and localized PLLA clustering can lead to complications and adverse events. This study developed a composite microneedle (MN) device comprising an array of PLLA microsphere (PLLA MP)-loaded hyaluronic acid needle tips with a supporting patch (PLLA MP-MN). This device was designed to deliver PLLA MPs precisely and uniformly to the dermis and to provide dual stimulation through MN puncture and MP implantation, thereby enabling the rapid and long-lasting regeneration of dermal collagen. When applied to rat skin, the MN array evenly distributed the PLLA MPs throughout the penetrated regions, which prevented local PLLA overdosing and elicited a milder inflammatory response compared with that induced by intradermal PLLA MP injections. An in vivo efficacy study revealed that MN-mediated delivery of PLLA MPs not only promptly initiated collagen production through microwound-triggered wound-healing cascades in the early treatment stage but also enabled the long-term stimulation of collagen deposition through MP-induced foreign body reactions, thereby significantly enhancing neocollagenesis. This innovative PLLA MP-MN system can augment the benefits and minimize the adverse effects associated with traditional PLLA fillers, providing a safe and reliable anti-aging therapeutic option.

Piezo1 Activation Drives Enhanced Collagen Synthesis in Aged Animal Skin Induced by Poly L-Lactic Acid Fillers.

Poly L-lactic acid (PLLA) fillers stimulate collagen synthesis by activating various immune cells and fibroblasts. Piezo1, an ion channel, responds to mechanical stimuli, including changes in extracellular matrix stiffness, by mediating Ca2+ influx. Given that elevated intracellular Ca2+ levels trigger signaling pathways associated with fibroblast proliferation, Piezo1 is a pivotal regulator of collagen synthesis and tissue fibrosis. The aim of the present study was to investigate the impact of PLLA on dermal collagen synthesis by activating Piezo1 in both an H2O2-induced cellular senescence model in vitro and aged animal skin in vivo. PLLA elevated intracellular Ca2+ levels in senescent fibroblasts, which was attenuated by the Piezo1 inhibitor GsMTx4. Furthermore, PLLA treatment increased the expression of phosphorylated ERK1/2 to total ERK1/2 (pERK1/2/ERK1/2) and phosphorylated AKT to total AKT (pAKT/AKT), indicating enhanced pathway activation. This was accompanied by upregulation of cell cycle-regulating proteins (CDK4 and cyclin D1), promoting the proliferation of senescent fibroblasts. Additionally, PLLA promoted the expression of phosphorylated mTOR/S6K1/4EBP1, TGF-β, and Collagen I/III in senescent fibroblasts, with GsMTx4 treatment mitigating these effects. In aged skin, PLLA treatment similarly upregulated the expression of pERK1/2/ERK1/2, pAKT/AKT, CDK4, cyclin D1, mTOR/S6K1/4EBP1, TGF-β, and Collagen I/III. In summary, our findings suggest Piezo1's involvement in PLLA-induced collagen synthesis, mediated by heightened activation of cell proliferation signaling pathways such as pERK1/2/ERK1/2, pAKT/AKT, and phosphorylated mTOR/S6K1/4EBP1, underscoring the therapeutic potential of PLLA in tissue regeneration.

Human Probiotic Lactobacillus paracasei-Derived Extracellular Vesicles Improve Tumor Necrosis Factor-α-Induced Inflammatory Phenotypes in Human Skin.

Lactic acid bacteria (LAB), a probiotic, provide various health benefits. We recently isolated a new Lactobacillus paracasei strain with strong anti-inflammatory effects under lipopolysaccharide-induced conditions and proposed a new mode of action-augmenting the endoplasmic reticulum stress pathway for anti-inflammatory functions in host cells. The beneficial effects of the L. paracasei strains on the skin have been described; however, the effects of L. paracasei-derived extracellular vesicles (LpEVs) on the skin are poorly understood. Herein, we investigated whether LpEVs can improve inflammation-mediated skin phenotypes by determining their effects on primary human skin cells and a three-dimensional (3D) full-thickness human skin equivalent under tumor necrosis factor (TNF)-α-challenged inflammatory conditions. LpEVs were efficiently taken up by the human skin cells and were much less cytotoxic to host cells than bacterial lysates. Furthermore, low LpEV concentrations efficiently restored TNF-α-induced cellular phenotypes, resulting in increased cell proliferation and collagen synthesis, but decreased inflammatory factor levels (matrix metalloproteinase 1, interleukin 6, and interleukin 8) in the human dermal fibroblasts, which was comparable to that of retinoic acid, a representative antiaging compound. The beneficial effects of LpEVs were validated in a 3D full-thickness human skin equivalent model. LpEV treatment remarkably restored the TNF-α-induced epidermal malformation, abnormal proliferation of keratinocytes in the basal layer, and reduction in dermal collagen synthesis. Additionally, LpEVs penetrated and reached the deepest dermal layer within 24 h when overlaid on top of a 3D full-thickness human skin equivalent. Furthermore, they possessed superior antioxidant capacity compared with the human cell-derived EVs. Taken together, the anti-inflammatory probiotic LpEVs can be attractive antiaging and antioxidant substances for improving inflammation-induced skin phenotypes and disorders.

Rapid on-demand in-situ gelling and dissociation of PEG bottlebrush hydrogel via light-mediated grafting-through polymerization for full-thickness skin wound repair

Developing light-triggered in situ forming dynamical hydrogels with on-demand dissolvable and antioxidation capacities to promote wound healing is highly desired yet challenging. Herein, we prepared an in situ forming bottlebrush hydrogel with on-demand dissolution capacity from two thioctic acid (TA)-functionalized poly(ethylene glycol)s (PEGs) telechelic (TA-PEGs) prepolymers via a light-mediated grafting-through polymerization strategy. In response to light irradiation, TA-PEGs could undergo rapid ring-opening polymerization to generate a highly branched bottlebrush network with dynamic disulfide bonds and simultaneously load water-soluble curcumin complexes with excellent antioxidant activity, enabling fast in situ gelation in 3 min to achieve perfect coverage of wound sites with different shapes. Furthermore, the resulting bottlebrush hydrogel dressing can achieve facile and painless removal of the dressing via rapid on-demand dissolution of the hydrogel during dressing changes. Meanwhile, thanks to its dynamical feature of the disulfide-based network, the hydrogel possesses excellent self-healing ability and shape adaptability that can maintain the interiority of the dressing during application and thus prolong its service life. In vitro evaluation demonstrates that this PEG bottlebrush hydrogel possesses favorable hemocompatibility, cytocompatibility, and antioxidant capacity. More importantly, in vivo experiments confirmed that the hydrogel promotes angiogenesis, dermal collagen synthesis, and alleviates the excessive ROS damage, thus providing more beneficial conditions to accelerate full-thickness skin wound healing.

Poly-L-Lactic Acid Fillers Improved Dermal Collagen Synthesis by Modulating M2 Macrophage Polarization in Aged Animal Skin.

Poly-L-lactic acid (PLLA) fillers correct cutaneous volume loss by stimulating fibroblasts to synthesize collagen and by augmenting the volume. PLLA triggers the macrophage-induced activation of fibroblasts that secrete transforming growth factor-β (TGF-β). However, whether M2 macrophage polarization is involved in PLLA-induced collagen synthesis via fibroblast activation in aged skin is not known. Therefore, we evaluated the effect of PLLA on dermal collagen synthesis via M2 polarization in an H2O2-induced cellular senescence model and aged animal skin. H2O2-treated macrophages had increased expression levels of the M1 marker CD80 and decreased expression levels of the M2 marker CD163, which were reversed by PLLA. The expression levels of interleukin (IL)-4 and IL-13, which mediate M2 polarization, were decreased in H2O2-treated macrophages and increased upon the PLLA treatment. CD163, IL-4, and IL-13 expression levels were decreased in aged skin, but increased after the PLLA treatment. The expression levels of TGF-β, pSMAD2/SMAD2, connective tissue growth factor (CTGF), alpha-smooth muscle actin (α-SMA), collagen type 1A1 (COL1A1), and COL3A1 were also decreased in aged skin, but increased after the PLLA treatment. Moreover, PLLA upregulated phosphatidylinositol 3-kinase p85α (PI3-kinase p85α)/protein kinase B (AKT) signaling, leading to fibroblast proliferation. PLLA decreased the expression of matrix metalloproteinase (MMP) 2 and MMP3, which destroy collagen and elastin fibers in aged skin. The amount of collagen and elastin fibers in aged skin increased following the PLLA treatment. In conclusion, PLLA causes M2 polarization by increasing IL-4 and IL-13 levels and upregulating TGF-β expression and collagen synthesis in aged skin.

Thermoresponsive Self-Healing Zwitterionic Hydrogel as an In Situ Gelling Wound Dressing for Rapid Wound Healing.

It is highly desired yet challenging to fabricate biocompatible injectable self-healing hydrogels with anti-bacterial adhesion properties for complex wounds that can autonomously adapt to different shapes and depths and can promote angiogenesis and dermal collagen synthesis for rapid wound healing. Herein, an injectable zwitterionic hydrogel with excellent self-healing property, good cytocompatibility, and antibacterial adhesion was developed from a thermoresponsive ABA triblock copolymer poly[(N-isopropyl acrylamide)-co-(butyl acrylate)-co-(sulfobetaine methacrylate)]-b-poly(ethylene glycol)-b-poly[(N-isopropyl acrylamide)-co-(butyl acrylate)-co-(sulfobetaine methacrylate)] (PZOPZ). The prepared PZOPZ hydrogel exhibits a distinct thermal-induced sol-gel transition around physiological temperature and could be easily applied in a sol state and in situ gelled to adapt complex wounds of different shapes and depths for complete coverage. Meanwhile, the hydrogel possesses a rapid self-healing ability and can recover autonomously from damage to maintain structural and functional integrity. In addition, the CCK-8 and 2D/3D cell culture experiments revealed that the PZOPZ hydrogel dressing shows low cytotoxicity to L929 cells and can effectively prevent the adhesion of Staphylococcus aureus and Escherichia coli. In vivo investigations verified that the PZOPZ hydrogel could increase angiogenesis and dermal collagen synthesis and shorten the transition from the inflammatory to the proliferative stage, thereby providing more favorable conditions for faster wound healing. Overall, this work provides a promising strategy to develop injectable zwitterionic hydrogel dressings with multiple functions for clinic wound management.

Topical growth factors and home-based microneedling for facial skin rejuvenation.

Cosmeceutical products are an important therapeutic option for facial rejuvenation. Of these, topical application of growth factors has been shown to increase dermal collagen synthesis, improve skin texture, and reduce fine lines and wrinkles. Limited data exist for the use of growth factors in combination with microneedling. This prospective, single-center, uncontrolled study evaluated the efficacy of topical growth factor treatment in conjunction with transdermal delivery of growth factors via home-based microneedling for facial skin rejuvenation. Eleven healthy female individuals aged 33-61years, with mild-moderate facial wrinkling were included in the study. Over 3months, participants received twice-daily application of a topical recombinant human growth factor preparation (SkinGenuity® Regenerative and Reparative Serums) along with twice-weekly transdermal delivery of growth factors using a home-based microneedling (0.2mm) device. Objective skin analysis (VISIA® ) and a subjective patient-reported outcome (FACE-Q® ) assessment measuring satisfaction with appearance were performed at baseline and after 3months. Objective skin analysis showed a significant improvement in skin texture (17.6%, p<0.001), wrinkles (17.3%, p<0.001), red areas (12.4%, p=0.004), and brown spots (6.0%, p=0.03) at 3months follow-up. FACE-Q scales showed a significant improvement from baseline, including satisfaction with skin, facial appearance, nasolabial folds, cheeks, and lower face/jawline (all p≤0.02). Numerical improvement in adverse effects related to skin was also observed (p=0.07). No serious adverse effects were reported. Three months of twice-daily topical growth factor treatment in conjunction with transdermal delivery of growth factors via microneedling improved skin analysis parameters and participant-reported outcome measures, indicative of facial skin rejuvenation.

VAP-PLGA microspheres (VAP-PLGA) promote adipose-derived stem cells (ADSCs)-induced wound healing in chronic skin ulcers in mice via PI3K/Akt/HIF-1α pathway

ABSTRACT Chronic skin ulcers are a primary global health problem. Velvet antler polypeptide (VAP) regulates endothelial cell migration and angiogenic sprout. Adipose-derived stem cells (ADSCs) are reported to make pivotal impacts upon wound healing. This study aimed to explore the role of VAP combined with ADSCs in wound healing of chronic skin ulcers. The effect of VAP on phenotypes of ADSCs, and VAP (PLGA microspheres) combining with ADSCs on wound healing of chronic skin ulcers in vivo was evaluated. VAP generally promoted the proliferation, migration and invasion of ADSCs, and ADSC-induced angiogenesis in human umbilical vein endothelial cells (HUVECs) through PI3K/Akt/HIF-1α pathway. VAP-PLGA (PLGA microspheres) enhanced the promoting effect of ADSCs on wound healing, pathological changes, and angiogenesis in chronic skin ulcers in vivo. VAP-PLGA intensified the effect of ADSCs on up-regulating the levels of p-PI3K/PI3K, p-Akt/Akt, HIF-1α, vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 (SDF-1), C-X-C motif chemokine receptor 4 (CXCR4), angiopoietin-4 (Ang-4), VEGF receptor (VEGFR), and transforming growth factor-β1 (TGF-β1), and down-regulating the levels of interleukin-1 β (IL-1β), IL-18 and IL-6 in wound tissues in chronic skin ulcers in vivo. Collectively, VAP promoted the growth, migration, invasion, and angiogenesis of ADSCs through activating PI3K/Akt/HIF-1α pathway, and VAP-PLGA enhanced the function of ADSCs in promoting wound healing in vivo, which was associated with angiogenesis, inflammation inhibition, and dermal collagen synthesis.

Low-molecular-weight whey proteins promote collagen production in dermal fibroblasts via the TGF-β receptor/Smad pathway.

Whey proteins (WPs) reportedly enhance cutaneous tissue regeneration in in vivo studies. However, the underlying mechanisms of such regenerative processes are poorly understood. In this study, we show that low-molecular-weight WPs (LMWPs; 1-30 kDa) accelerate the dermal collagen production via the transforming growth factor β receptor (TβR)/Smad pathway. We showed that LMWPs increased type I and III collagen expression in normal human dermal fibroblasts. Moreover, LMWPs rapidly induced Smad protein phosphorylation and nuclear translocation. Notably, type I TβR/Smad signaling inhibitor treatment or type II TβR siRNA knockdown blocked the LMWP-induced type I collagen expression. To identify the active components, we fractionated LMWPs and identified β-lactoglobulin and α-lactalbumin as potential TβR/Smad signaling inducers. Our findings unravel novel biological functions of WPs, involving the TβR/Smad-dependent induction of dermal collagen synthesis, highlighting the therapeutic potential of LMWPs in wound healing.

Potential for tyndalized Lactobacillus acidophilus as an effective component in moisturizing skin and anti-wrinkle products.

It is widely accepted that ultraviolet (UV) irradiation induces skin damage. In the present study, a UVB-induced hairless mouse model of skin photoaging was developed to determine whether tyndalized Lactobacillus acidophilus was able to significantly enhance the repair of photodamaged skin. To evaluate the effects of tyndalized L. acidophilus on UVB-induced skin-wrinkle formation in vivo, HR-1 hairless male mice were exposed to UVB radiation and orally administered tyndalized L. acidophilus. Compared with the control group, the UVB irradiation mice displayed a significant increase in transepidermal water loss and a reduction in skin hydration. In mice with UVB-induced photodamage, the effacement of the fine wrinkles by tyndalized L. acidophilus was correlated with dermal collagen synthesis, accompanied by histological changes. Furthermore, western blotting was performed to investigate the protein expression levels of matrix metalloproteinases (MMPs) and mitogen-activated protein kinase. Notably, orally administered tyndalized L. acidophilus reduced the expression levels of MMP-1 and MMP-9. Based upon the aforementioned results, it was determined that tyndalized L. acidophilus effectively inhibited the wrinkle formation induced by UVB irradiation, and that this may be attributed to the downregulation of MMPs. Therefore, tyndalized L. acidophilus may be considered a potential agent for preventing skin photoaging and wrinkle formation.

Inhibitory effect of ciprofloxacin on bleomycin-induced dermal fibrosis in mice

Objective To investigate the effects of ciprofloxacin on dermal collagen synthesis and profibrotic gene expressions in an experimental mouse model of scleroderma induced by bleomycin. Methods Experimental mouse models of scleroderma were established by subcutaneous injection of bleomycin into the dorsal skin of 15 BALB/c mice for 4 consecutive weeks. Then, the mouse models were randomly and equally divided into 3 groups to be topically treated with 1% ciprofloxacin cream (ciprofloxacin group), 2.5% asiaticoside cream (asiaticoside group) and cream vehicle (model group) respectively for 5 consecutive weeks. Five mice firstly injected with sterile phosphate buffered saline (PBS) for 4 weeks then topically treated with cream vehicle for 5 weeks served as the blank control group. After the 5-week topical treatment, all the mice were sacrificed, skin specimens were resected from the dorsal skin of them, and subjected to HE staining and Masson staining. Further more, an immunohistochemical assay was performed to measure the expressions of type I collagen (COL-1), matrix metalloproteinase-1 (MMP1) and tissue inhibitor of matrix metalloproteinase-1 (TIMP1), semi-quantitative reverse transcription PCR to quantify the expressions of connective tissue growth factor (CTGF), transforming growth factor-β1 (TGFβ1) and Smad3 genes, and alkaline hydrolysis-spectrophotometry to determine the level of hydroxyproline in skin. Statistical analysis was carried out by one-way analysis of variance and the least significant difference (LSD) test with the SPSS 17.0 software. Results Compared with the blank control group, the model group showed increased dermal thickness at injection sites (432.76±93.74 μm vs. 301.69±79.47 μm, P 0.05). Moreover, compared with cream vehicle, asiaticoside down-regulated the expressions of the three profibrotic genes (CTGF, TGFβ1 and Smad3) to different extents (all P 0.05). Conclusion Ciprofloxacin may counteract dermal fibrosis by inhibiting the TGFβ1/Smad3 pathway and modulating the unbalanced expressions of MMP1 and TIMP1. Key words: Ciprofloxacin; Scleroderma, localized; Fibrosis; Collagen; Bleomycin; Models, animal

β-Cyclodextrin-Linked Polyethylenimine Nanoparticles Facilitate Gene Transfer and Enhance the Angiogenic Capacity of Mesenchymal Stem Cells for Wound Repair and Regeneration.

Repair of deep wounds by cell transplantation strongly depends on angiogenesis and on the regeneration of skin and appendages. In this study, plasmid DNA encoding vascular endothelial growth factor-165 (VEGF-165) was transduced into bone-marrow mesenchymal stem cells (MSCs) using a nonviral vector, β-cyclodextrin-linked polyethylenimine, to enhance angiogenic capacity. The effects of MSCs administered by intradermal injection or transplantation on wound closure were compared in a full-thickness excision wound model. The results showed that the MSC-seeded sponge had significantly stronger acceleration in wound closure than the MSC injection. The effects on wound repair and regeneration of transplanted MSCs and pDNA-VEGF1 65-transfected MSCs (TMSCs) with gelatin/β-tricalcium phosphate scaffold were also investigated. Compared with MSC transplantation, TMSC transplantation showed higher efficacy in stimulating wound closure, promoting dermal collagen synthesis and regulating the deposition of newly formed collagen. In addition, the angiogenic capacity of the TMSCs was higher than that of the MSCs. The results indicate that the nonviral genetic engineering of the MSCs is a promising strategy to enhance the angiogenic capacity of MSCs for wound repair and angiogenesis. Functional gene-activated MSCs may be used as cost-effective and accessible seed cells for skin tissue engineering and as novel carriers for wound gene therapy.

Enhanced cutaneous bioavailability of dehydroepiandrosterone mediated by nano-encapsulation

Polymeric nanocarriers, especially nanospheres (NSs) and nanocapsules (NCs), can promote the penetration of their cargo through the skin barrier, towards improved cutaneous bioavailability. Dehydroepiandrosterone (DHEA), an endogenous hormone exhibiting poor aqueous solubility, was shown to be effective in modulating skin-aging processes following topical application. In this study, we designed adequate DHEA preparations, in an attempt to enable local delivery of the active ingredient to the viable skin layers. In addition, the potential efficiency of DHEA NCs on dermal collagen synthesis was evaluated. Cryo-TEM observations and thermal analysis indicated that DHEA was successfully incorporated within a stable NC-based delivery system. Moreover, higher [3H]-DHEA levels were recorded in the viable skin layers following different incubation periods of NCs on excised pig skin specimens as compared to DHEA oil solution (free molecule). Furthermore, significantly higher (4-fold) skin flux values were observed for the DHEA NCs as compared to the values elicited by the oil control solution. Finally, collagen synthesis in human skin organ culture, assessed by the incorporation of [3H]-proline, was up to 42% higher for DHEA NCs 48h post-topical application than for the untreated specimens. Overall, these results suggest that poly lactic-co-glycolic acid (PLGA)-based NCs have promising potential to be used topically for various skin disorders.

Bleomycin‐induced fibrosis in MC1 signalling‐deficient C57BL/6J‐Mc1re/e mice further supports a modulating role for melanocortins in collagen synthesis of the skin

The melanocortin-1 receptor (MC1 ) binds α-melanocyte-stimulating hormone (α-MSH) with high affinity and has a physiological role in cutaneous melanin pigmentation. Previously, we reported that human dermal fibroblasts also express functional MC1 . α-MSH suppressed transforming growth factor-β1 - and bleomycin (BLM)-induced collagen synthesis in vitro and in vivo. Using MC1 signalling-deficient C57BL/6J-Mc1r(e/e) mice, we tested as to whether MC1 has a regulatory role on dermal collagen synthesis in the BLM model of scleroderma. Notably, mice with a C57BL/6J genetic background were previously shown to be BLM-non-susceptible. Interestingly, treatment of C57BL/6J-Mc1r(e/e) but not of C57BL/6J-wild-type mice with BLM increased cutaneous collagen type I content at RNA and protein level along with development of skin fibrosis. Cutaneous levels of connective tissue growth factor and monocyte chemotactic protein-1 were also increased in BLM-treated C57BL/6J-Mc1r(e/e) mice. Primary dermal fibroblasts from C57BL/6J-wt mice further expressed MC1 , suggesting that these cells are directly targeted by melanocortins to affect collagen production of the skin. Our findings support the concept that MC1 has an endogenous regulatory function in collagen synthesis and controls the extent of fibrotic stress responses of the skin.

Epidermal Stem Cells Manipulated by pDNA-VEGF165/CYD-PEI Nanoparticles Loaded Gelatin/β-TCP Matrix as a Therapeutic Agent and Gene Delivery Vehicle for Wound Healing

The success of gene therapy largely relies on a safe and effective gene delivery system. The objective of this study is to design a highly efficient system for the transfection of epidermal stem cells (ESCs) and investigate the transfected ESCs (TESCs) as a therapeutic agent and gene delivery reservoir for wound treatment. As a nonviral vector, β-cyclodextrin-linked polyethylenimines (CYD-PEI) was synthesized by linking β-cyclodextrin with polyethylenimines (600 Da). Gelatin scaffold incorporating β-tricalcium phosphate (β-TCP) was utilized as a substrate for the culture and transfection of ESCs. With the CYD-PEI/pDNA-VEGF165 polyplexes incorporated gelatin/β-TCP scaffold based 3D transfection system, prolonged VEGF expression with a higher level was obtained at day 7 in ESCs than those in two-dimensional plates. Topical application of the TESCs significantly accelerated the skin re-epithelization, dermal collagen synthesis, and hair follicle regeneration. It also exhibited a potential in scar inhibition by regulating the distribution of different types of collagen. In contrast to ESCs, an additive capacity in stimulating angiogenesis at the wound site was observed in the TESCs. The present study provides a basis for the TESCs as a promising therapeutic agent and gene delivery reservoir for wound therapy.

Accelerated healing of diabetic wound using artificial dermis constructed with adipose stem cells and poly(L-glutamic acid)/chitosan scaffold

Background Diabetic wound is one of the most serious complications of diabetes mellitus. There are no significantly effective therapies for chronic non-healing diabetes ulcer so far. This study aimed to explore the feasibility of healing impaired wound using artificial dermis constructed with human adipose derived stem cells (ASCs) and poly(L-glutamic acid)/chitosan (PLGA/CS) scaffold in streptozotocin-induced diabetic mice. Methods ASCs were isolated from fresh human lipoaspirates and expanded ex vivo for three passages, and then cells were seeded onto PLGA/CS scaffold to form artificial dermis. Expression of VEGF and TGFβ1 by ASCs presented in artificial dermis was determined. The artificial dermis was transplanted to treat the 20 mm × 20 mm full-thickness cutaneous wound created on the back of diabetic mice. Wound treated with scaffold alone and without treatment, and wound in normal non-diabetic mice served as control. Results Cells growing within scaffold showed great proliferation potential, depositing abundant collagen matrix. Meanwhile, expression of VEGF and TGF-β1 by seeded ASCs maintained at a consistent high level. After treated with ASC based artificial dermis, diabetic wounds exhibited significantly higher healing rate compared with wounds treated with scaffold alone or without treatment. Histological examination also demonstrated an improvement in cutaneous restoration with matrix deposition and organization. Further quantitative analysis showed that there was a significant increase in dermis thickness and collagen content on artificial dermis treated wounds. Conclusion ASC/PLGA artificial dermis can effectively accelerate diabetic wound healing by promoting angiogenic growth factors and dermal collagen synthesis.

Transplantation of bone-marrow-derived mesenchymal and epidermal stem cells contribute to wound healing with different regenerative features

A new concept for wound therapy is the initiation of the regeneration of epidermal and dermal layers with appendages for skin function recovery. Bone-marrow-derived mesenchymal and epidermal stem cells (BMSCs and SSCs) are hypothesized to be able to home toward or to be transplanted to wound sites for skin repair and regeneration, but this awaits confirmation by further experimental and clinical evidence. In this study, the influence of the transplantation of BMSCs and SSCs with porous gelatin-β-tricalcium phosphate sponge as scaffolds on wound re-epithelization, collagen synthesis, skin tensile strength recovery, and skin appendage regeneration has been investigated. The transplantation of BMSCs or SSCs significantly accelerates wound re-epithelization, stimulates dermal collagen synthesis, and exhibits the trend to enhance the tensile strength recovery of skin. Furthermore, regenerative features of BMSCs and SSCs have been identified in activating blood vessel and hair follicle formation, respectively. These results not only provide experimental evidence for the application of BMSCs and SSCs as promising therapeutics for clinical wound treatment, but also display their characteristics in activating distinct skin appendage regeneration, which might have novel applications in skin tissue engineering.

The transcriptional role of BBF2H7, ER stress transducer, during collagen biosynthesis in dermal fibroblasts

BBF2 human homolog on chromosome 7 (BBF2H7), a member of the CREB/ATF family, is an endoplasmic reticulum (ER) stress transducer. BBF2H7 functions as a transcription factor to regulate expression of Sec23A, which encodes a coat protein complex II component responsible for protein transport from the ER to the Golgi. We have previously shown that BBF2H7 in normal human dermal fibroblasts (NHDFs) is involved in collagen synthesis in response to insulin growth factor-I (IGF-I), and that the BBF2H7-Sec23A pathway is required for ER-to-Golgi collagen trafficking. However, it is uncertain whether this pathway is also engaged in other cytokine stimulus-responsive collagen synthesis in dermal fibroblasts. Herein, we demonstrate a new pathway activating BBF2H7 in response to transforming growth factor-beta (TGF-β), which maintains dermal collagen homeostasis as well as IGF-I. TGF-β increased the expression levels of mRNA and protein of type I collagen (COL1) in NHDFs. The expression of BBF2H7 markedly elevated at earlier time points, whereas that of Sec23A was very similar to that of COL1. Furthermore, BBF2H7 knockdown caused a significant reduction in the expression of COL1 and Sec23A induced by TGF-β stimulation. These results suggest that BBF2H7 in NHDFs regulates the expression of COL1 and Sec23A in response to TGF-β. Pretreatment of SB431542, a specific TGF-β receptor type I kinase inhibitor, completely suppressed the expression of BBF2H7 and Sec23A induced by TGF-β stimulation, indicating that TGF-β-inducible activation of BBF2H7-Sec23A pathway is triggered by a ligand binding event. Our results raise the possibility that BBF2H7 plays a key role in dermal collagen synthesis constitutively regulated via several routes, contributing to provide novel anti-ageing strategies. JSID AbstractsJournal of Dermatological ScienceVol. 69Issue 2Preview Full-Text PDF

BBF2H7-Mediated Sec23A Pathway Is Required for Endoplasmic Reticulum-to-Golgi Trafficking in Dermal Fibroblasts to Promote Collagen Synthesis

Collagen fibers, structural elements responsible for mechanical strength in skin, are synthesized constitutively in response to cytokines such as IGF-I. However, little is known about their intracellular trafficking from the endoplasmic reticulum (ER) to the Golgi apparatus during synthesis. We demonstrate herein that the BBF2 human homolog on chromosome 7 (BBF2H7)-mediated Sec23A pathway is involved in regulation of intracellular procollagen trafficking. The mRNA and protein expression of BBF2H7, Sec23A, and type I and III collagen (COL1 and COL3) was induced by IGF-I stimulation. In addition, the cleaved form of BBF2H7 was detected in IGF-I-treated cultures, indicating that activation occurs concurrently with its expression. Knockdown with small interfering RNAs targeting BBF2H7 caused a significant reduction in the expression of COL1 and COL3, regardless of IGF-I treatment. Both mitogen-activated protein kinase and phosphatidylinositol-3 kinase pathways via IGF-I receptor activation were required for BBF2H7 induction. Using immunofluorescence microscopy, we showed that Golgi apparatus dysmorphology is due to coat protein complex II vehicle hypoplasia caused by the absence of BBF2H7 and Sec23A. The BBF2H7-mediated Sec23A pathway was required for ER-to-Golgi procollagen trafficking to promote collagen synthesis. This role of growth factors such as IGF-I, which to our knowledge is previously unreported, suggests antiaging strategies.