Growth factors (GFs) are a class of peptides that facilitate cell growth by binding to specific receptors on the cell membrane. With unique properties, GFs are widely applied in the repair of injured tissue. To address the limitations associated with natural peptide-based GFs and recombinant GFs, researchers have developed diverse GF mimetics. This article offers a comprehensive review on common types of GFs and their applications in tissue repair and summarizes the features of GF mimetics currently under development. The aim is to provide valuable references for promoting the application of GFs in regenerative medicine.
Intercellular Signaling Peptides and Proteins/therapeutic use* ; Humans ; Tissue Engineering/methods* ; Regenerative Medicine/methods* ; Animals ; Wound Healing/drug effects* ; Biomimetic Materials

Diabetic chronic wounds are characterized by difficult healing, recurrent progression, and high rates of disability and mortality, which make their clinical treatment a medical challenge urgent to be addressed. However, the complex local microenvironment conditions of chronic wounds, such as high protease activity and persistent inflammatory responses, result in low bioavailability of exogenous cytokines (e.g., chemokine CXCL12) at the wound site, limiting their clinical application. In this study, we utilized Lactobacillus plantarum WCFS1 as the chassis to develop an efficient CXCL12 delivery system based on synthetic biology. Subsequently, we evaluated the role of the engineered probiotic strain in promoting the chronic wound healing in diabetic mice. Firstly, we fused the endogenous secretion signal peptide lp_3050 (SP_{lp_3050}) of L. plantarum WCFS1 and the commonly used secretion signal peptide usp45 (SP_usp45) of lactic acid bacteria with the reporter gene gusA and inserted them into the pTRK892-P_32(pgm) plasmid by molecular cloning. Then, we prepared the engineered strains and characterized the efficacy of the two signal peptides in driving the secretion of GusA. The results showed that SP_{lp_3050} efficiently drove the secretion of GusA in L. plantarum WCFS1, increasing the activity of GusA in the culture supernatant by nearly five times compared with that of SP_{lp_3050}. Further, we fused SP_{lp_3050} and codon-optimized CXCL12 gene to construct an engineered probiotic strain Lpw-CXCL12 for CXCL12 delivery. The results demonstrated that the content of CXCL12 in the culture supernatant reached (13.40±0.20) μg/mL. Finally, we found that the engineered probiotic strain Lpw-CXCL12 accelerated chronic wound healing in a diabetic mouse model. In conclusion, these results support an engineered probiotic strain in promoting diabetic chronic wound healing, providing a new strategy and technological foundation for the management of diabetic chronic wounds in the future.
Probiotics ; Animals ; Chemokine CXCL12/biosynthesis* ; Mice ; Wound Healing ; Lactobacillus plantarum/metabolism* ; Diabetes Mellitus, Experimental/complications* ; Male

Chronic non-healing wounds significantly impair patient rehabilitation and remain a critical clinical challenge. Stem cell-derived exosomes, owing to their biocompatibility and physiological activity, have emerged as a promising therapeutic approach in regenerative medicine. Beyond their intrinsic wound-healing properties, exosomes are increasingly explored as carriers for small-molecule drugs to enhance synergistic treatment effects. Although microRNAs (miRNAs) exhibit potential in promoting cell proliferation and re-epithelialization, their clinical application is hindered by poor stability. In this study, we investigated the therapeutic effects of miR-132-3p-loaded human umbilical mesenchymal stem cell-derived exosomes (miR-132-3p@UMSC-EXOs) on human foreskin fibroblast-1 (HFF-1). Our findings demonstrated that miR-132-3p@UMSC-EXOs significantly enhanced proliferation and migration of HFF-1, while reducing intracellular reactive oxygen species (ROS) levels compared with unloaded exosomes. Furthermore, qRT-PCR and Western blotting analyses revealed that miR-132-3p@UMSC-EXOs modulated the expression of genes associated with extracellular matrix (ECM) remodeling and inflammation, suggesting their potential to upregulate collagen synthesis and improve ECM metabolism. These results highlight the therapeutic promise of miR-132-3p@UMSC-EXOs in accelerating wound healing.
Humans ; MicroRNAs/pharmacology* ; Exosomes/metabolism* ; Mesenchymal Stem Cells/cytology* ; Wound Healing ; Umbilical Cord/cytology* ; Cell Proliferation ; Fibroblasts/cytology* ; Skin/injuries* ; Cell Movement ; Reactive Oxygen Species/metabolism* ; Cells, Cultured

This study evaluated the healing-promoting effect and applicability of seven new dressings in chronic wounds. A chronic wound model was established using 48 db/db diabetic mice, which were randomly divided into 8 groups (control, polymer film, alginate, foam, hydrocolloid, hydrogel, carbon fiber, and silver dressing groups). Regular monitoring was conducted on the 5, 10, 15, and 20 days after surgery, and a comprehensive evaluation was performed based on healing rate, characteristic of histopathology, and semi-quantitative scoring. The results showed that, except for the polymer film dressing group, all other dressing groups had significantly better healing-promoting effect than the control group ( P＜0.05), with the hydrocolloid, carbon fiber, and silver dressing groups demonstrated particularly outstanding efficacy. This study systematically compared the efficacy differences of seven dressings, and combined them with the adhesion, exudate volume and infection risks to provide a scientific basis for clinical dressing selection.
Animals ; Mice ; Wound Healing ; Bandages ; Male ; Diabetes Mellitus, Experimental ; Disease Models, Animal

OBJECTIVE: To investigate the biological effect of medical recombinant human-derived collagen functional dressings in wound healing. METHODS: MTT assay and RTCA assay were used to detect cell toxicity and proliferation. Scratch assay and Transwell cell migration assay were used to detect cell motility and migration ability. Enzyme-linked immunosorbent assay was used to detect the contents of vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and platelet-endothelial cell adhesion molecule (CD31) in the supernatant of four types of cells. After animal surgery, the surgical wound was taken at 1 week, 4 weeks and 13 weeks, respectively, for hematoxylin eosin (HE) staining and immunohistochemistry to observe the inflammatory response and CD31 expression of the wound. RESULTS: Medical recombinant human-derived collagen functional dressing promotes cell proliferation and migration, enhances wound angiogenesis by upregulating the expression of VEGF, FGF, and CD31 in human dermal vascular endothelial cells (HDVEC) and human vascular endothelial cells (HVEC), thereby improving local blood supply to the wound, regulating the inflammatory response of the wound, and accelerating wound healing. CONCLUSION Recombinant type Ⅲ humanized collagen plays an important role in wound healing.
Humans ; Wound Healing/drug effects* ; Recombinant Proteins/pharmacology* ; Animals ; Cell Proliferation ; Cell Movement ; Collagen/pharmacology* ; Vascular Endothelial Growth Factor A/metabolism* ; Bandages ; Platelet Endothelial Cell Adhesion Molecule-1/metabolism* ; Endothelial Cells ; Fibroblast Growth Factors/metabolism*

OBJECTIVE: To investigate the clinical effects of thread-dragging therapy on gangrene of non-ischemic diabetic foot ulcers (NIDFU). METHODS: A total of 136 patients with NIDFU were recruited from the Department of Peripheral Vascular Surgery, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine between June 21, 2021 and February 1, 2023, and randomized into an intervention group and a control group, with 68 cases in each group. Both groups received basic treatment. The intervention group was treated with thread-dragging therapy, while the control group was treated with debridement combined with routine dressing changes after surgery. Both groups were treated continuously for 2 months. The amputation rates and changes in the ulcer area were compared between the groups. The inflammatory response index including peripheral white blood cells (WBCs), neutrophil percentage (NEUT%), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), and interleukin 6 (IL-6) were compared between the two groups. RESULTS: After treatment, the ulcer areas in the intervention group were significantly smaller than that of the control group (8.50±3.88 cm² vs. 10.11±4.61 cm², P<0.05). The amputation rates of the two groups were not statistically significant (4.4% vs. 5.9%, P>0.05). Differences of WBCs count, CRP, and ESR before and after therapy in the intervention group were better than the control group (P<0.05). However, there were no significant differences in changes of NEUT%, PCT, and IL-6 between the two groups (P>0.05). CONCLUSION Thread-dragging therapy may be effective in the treatment of NIDFU, with the additional advantages of less tissue damage after healing. (Registration No. ChiCTR2100047496).
Humans ; Diabetic Foot/blood* ; Male ; Female ; Middle Aged ; Gangrene/therapy* ; Medicine, Chinese Traditional/methods* ; Aged ; C-Reactive Protein/metabolism* ; Amputation, Surgical ; Wound Healing ; Treatment Outcome ; Interleukin-6/blood*

With the continuous advancement of deep space exploration missions, maintaining astronaut skin health has become a critical medical issue affecting the safety and effectiveness of long-duration missions. Deep space environmental stressors, including microgravity, ionizing radiation, lunar dust exposure, and microbiome dysbiosis, can synergistically disrupt the skin barrier structure, leading to immune homeostasis imbalance and impaired wound healing. In recent years, research on skin protection in deep space has gradually evolved into a systematic "multi-dimensional integrated protective" framework. From the engineering protection perspective, optimization of multi-layer composite spacesuit structures, the use of hydrogen-rich and boron-containing shielding materials, as well as cabin temperature-humidity regulation and debris-resistant technologies, have greatly enhanced environmental defense capacity. From the biomedical protection perspective, functional hydrogels, antimicrobial dressings, and active compounds derived from traditional Chinese medicine have demonstrated remarkable potential in repairing the skin barrier, modulating immunity, and providing antioxidant defense. Meanwhile, the development of skin microecological interventions and wearable physiological monitoring systems has fostered a trend toward personalized health management. Future research should focus on elucidating the interactive mechanisms among the space environment, skin, and immune barrier, while exploring intelligent monitoring and nanotechnology-based protection strategies. Establishing a predictive and preventive skin health safeguarding system will provide comprehensive medical support for future deep space missions.
Humans ; Astronauts ; Skin/radiation effects* ; Space Flight ; Weightlessness/adverse effects* ; Wound Healing ; Extraterrestrial Environment

OBJECTIVES: To evaluate the photothermal and antibacterial activities of polydopamine-modified phycocyanin nanoparticles (PDA@PC NPs) and their capacity for promoting wound healing. METHODS: PDA@PC NPs were synthesized from phycocyanin (C-PC) and dopamine hydrochloride using a one-pot method. The photothermal activity of the nanoparticles was assessed in vitro by 808 nm laser irradiation, their biocompatibility was evaluated using CCK-8 assay, and their photothermal antibacterial activity by plate colony counting. In adult male BALB/c mice, two symmetrical full-thickness skin wounds (1.0 cm ×1.0 cm) were created on both sides of the spine, and 200 μL of Staphylococcus aureus suspension was inoculated into the wounds. The mice were divided into control group, PDA@PC NPs group, and PDA@PC NPs with laser irradiation group, and wound healing rates and histomorphological changes in the wound tissues were evaluated on days 0, 7 and 14 after modeling. RESULTS: The synthesized PDA@PC NPs exhibited no obvious cytotoxicity up to a concentration of 500 μg/mL and showed strong photothermal and antibacterial activities in response to 808 nm laser irradiation. In the mouse models, the size of the infected skin wounds showed substantial reduction at 7 and 14 days in PDA@PC NPs group and PDA@PC NPs with laser irradiation group, and the mean wound healing rate was faster in the latter group. HE staining and Masson's trichrome staining revealed extensive granulation tissue formation and collagen deposition on the wound surfaces in both of the treatment groups, and these changes were more obvious in the PDA@PC NPs with laser irradiation group. CONCLUSIONS PDA@PC NPs possess excellent photothermal and antibacterial activities and can effectively promote wound healing in mice.
Animals ; Indoles/chemistry* ; Wound Healing/drug effects* ; Mice ; Mice, Inbred BALB C ; Male ; Nanoparticles ; Polymers/chemistry* ; Phycocyanin/chemistry* ; Skin/injuries* ; Staphylococcus aureus/drug effects* ; Anti-Bacterial Agents/pharmacology*

OBJECTIVES: To investigate the mechanism by which chitosan (CS) hydrogel loaded with human umbilical cord mesenchymal stem cell (HUVECs)-derived exosomes (hUCMSC-exos) (Exos@CS-Gel) improves diabetic wound healing. METHODS: hUCMSC-exos were extracted and Exos@CS-Gel was prepared. The effect of Exos@CS-Gel on proliferation and migration of HUVECs were evaluated using scratch wound assay and CCK-8 assay. Diabetic rat models with full-thickness skin wounds established by streptozotocin induction were randomized divided into 4 groups for treatment with Exos@CS-Gel (100 µg hUCMSC-exos dissolved in 100 µL 24% CS hydrogel), hUCMSC-exos (100 µg hUCMSC-exos dissolved in 100 µL PBS), CS hydrogel (100 µL 24% CS hydrogel), or PBS (control group). Wound healing and the therapeutic mechanisms were assessed using immunohistochemistry, HE staining, immunofluorescence, and qRT-PCR. RESULTS: In cultured HUVECs, Exos@CS-Gel treatment significantly promoted cell proliferation and migration. In the rat models of chronic diabetic wounds, the wound healing rate in Exos@CS-Gel group reached 92.7% on day 14, significantly higher than those in hUCMSC-exos group (9.12%), CS hydrogel group (16.28%), and control group (25.98%). Microvessel density and the expression levels of vascular endothelial growth factor and transforming growth factor β-1 were significantly increased in the Exos@CS-Gel group. CONCLUSIONS Exos@CS-Gel promotes survival capacity of hUCMSC-exos in vitro and accelerates diabetic wound healing in rats by promoting angiogenesis and cell proliferation.
Animals ; Wound Healing ; Humans ; Chitosan ; Exosomes ; Mesenchymal Stem Cells/cytology* ; Diabetes Mellitus, Experimental ; Rats ; Umbilical Cord/cytology* ; Hydrogels ; Human Umbilical Vein Endothelial Cells ; Cell Proliferation ; Rats, Sprague-Dawley ; Male

Frostbite is the most common cold injury and is caused by both immediate cold-induced cell death and the gradual development of localized inflammation and tissue ischemia. Delayed healing of frostbite often leads to scar formation, which not only causes psychological distress but also tends to result in the development of secondary malignant tumors. Therefore, a rapid healing method for frostbite wounds is urgently needed. Herein, we used a mouse skin model of frostbite injury to evaluate the recovery process after frostbite. Moreover, single-cell transcriptomics was used to determine the patterns of changes in monocytes, macrophages, epidermal cells, and fibroblasts during frostbite. Most importantly, human-induced pluripotent stem cell (hiPSC)-derived skin organoids combined with gelatin-hydrogel were constructed for the treatment of frostbite. The results showed that skin organoid treatment significantly accelerated wound healing by reducing early inflammation after frostbite and increasing the proportions of epidermal stem cells. Moreover, in the later stage of wound healing, skin organoids reduced the overall proportions of fibroblasts, significantly reduced fibroblast-to-myofibroblast transition by regulating the integrin α5β1-FAK pathway, and remodeled the extracellular matrix (ECM) through degradation and reassembly mechanisms, facilitating the restoration of physiological ECM and reducing the abundance of ECM associated with abnormal scar formation. These results highlight the potential application of organoids for promoting the reversal of frostbite-related injury and the recovery of skin functions. This study provides a new therapeutic alternative for patients suffering from disfigurement and skin dysfunction caused by frostbite.
Animals ; Organoids/metabolism* ; Mice ; Humans ; Wound Healing ; Frostbite/metabolism* ; Skin/pathology* ; Induced Pluripotent Stem Cells/cytology* ; Cicatrix/pathology* ; Fibroblasts/metabolism* ; Disease Models, Animal ; Mice, Inbred C57BL ; Extracellular Matrix/metabolism* ; Male