Recent advances in the use of extracellular vesicles from adipose-derived stem cells for regenerative medical therapeutics.

Adipose-derived stem cells (ADSCs) are a subset of mesenchymal stem cells (MSCs) isolated from adipose tissue. They possess remarkable properties, including multipotency, self-renewal, and easy clinical availability. ADSCs are also capable of promoting tissue regeneration through the secretion of various cytokines, factors, and extracellular vesicles (EVs). ADSC-derived EVs (ADSC-EVs) act as intercellular signaling mediators that encapsulate a range of biomolecules. These EVs have been found to mediate the therapeutic activities of donor cells by promoting the proliferation and migration of effector cells, facilitating angiogenesis, modulating immunity, and performing other specific functions in different tissues. Compared to the donor cells themselves, ADSC-EVs offer advantages such as fewer safety concerns and more convenient transportation and storage for clinical application. As a result, these EVs have received significant attention as cell-free therapeutic agents with potential future application in regenerative medicine. In this review, we focus on recent research progress regarding regenerative medical use of ADSC-EVs across various medical conditions, including wound healing, chronic limb ischemia, angiogenesis, myocardial infarction, diabetic nephropathy, fat graft survival, bone regeneration, cartilage regeneration, tendinopathy and tendon healing, peripheral nerve regeneration, and acute lung injury, among others. We also discuss the underlying mechanisms responsible for inducing these therapeutic effects. We believe that deciphering the biological properties, therapeutic effects, and underlying mechanisms associated with ADSC-EVs will provide a foundation for developing a novel therapeutic approach in regenerative medicine.

Short- and Long-Term Outcome of Selective Reduction by Fetoscopy-Guided Bipolar Cord Coagulation in Monochronic Twin Pregnancies.

INTRODUCTION: The aim of this study was to assess the short- and long-term outcome of selective reduction by fetoscopy-guided bipolar cord coagulation in monochronic twin pregnancies. METHODS: Retrospective analysis was conducted of a consecutive cohort of all monochorionic twin pregnancies treated with fetoscopy-guided bipolar cord coagulation between December 2015 and December 2022 in a single center in China. RESULTS: A total of 43 monochronic twin pregnancies undergoing fetoscopy-guided bipolar cord coagulation were analyzed. There were 5 intrauterine deaths with an 88.4% (38/43) survival rate overall. The preterm premature rupture of the membranes rate was 13.2%, and the preterm birth before 37 and 32 weeks was 42.1% and 13.1%, respectively. An uptrend in the survival rate (78.9 vs. 95.8%, p = 0.086) and a downtrend of procedure time (30 vs. 16.5 min, p = 0.036) were observed over time (period 1 from December 2015 to December 2019 verses period 2 from January 2020 to December 2022). Long-term outcome was assessed in 94.6% (35/37) of survivors, and 91.4% (32/35) had normal neurodevelopmental outcome. CONCLUSION: Fetoscopy-guided bipolar cord coagulation for fetal reduction in complicated monochorionic twin pregnancies could achieve a favorable short- and long-term outcome, especially in experienced hands.

All-in-One: Multifunctional Hydrogel Accelerates Oxidative Diabetic Wound Healing through Timed-Release of Exosome and Fibroblast Growth Factor.

The treatment of diabetic wounds remains a major challenge in clinical practice, with chronic wounds characterized by multiple drug-resistant bacterial infections, angiopathy, and oxidative damage to the microenvironment. Herein, a novel in situ injectable HA@MnO2 /FGF-2/Exos hydrogel is introduced for improving diabetic wound healing. Through a simple local injection, this hydrogel is able to form a protective barrier covering the wound, providing rapid hemostasis and long-term antibacterial protection. The MnO2 /ε-PL nanosheet is able to catalyze the excess H2 O2 produced in the wound, converting it to O2 , thus not only eliminating the harmful effects of H2 O2 but also providing O2 for wound healing. Moreover, the release of M2-derived Exosomes (M2 Exos) and FGF-2 growth factor stimulates angiogenesis and epithelization, respectively. These in vivo and in vitro results demonstrate accelerated healing of diabetic wounds with the use of the HA@MnO2 /FGF-2/Exos hydrogel, presenting a viable strategy for chronic diabetic wound repair.

Metformin alleviates bone loss in ovariectomized mice through inhibition of autophagy of osteoclast precursors mediated by E2F1.

BACKGROUND: Postmenopausal bone loss, mainly caused by excessive bone resorption mediated by osteoclasts, has become a global public health burden. Metformin, a hypoglycemic drug, has been reported to have beneficial effects on maintaining bone health. However, the role and underlying mechanism of metformin in ovariectomized (OVX)-induced bone loss is still vague. RESULTS: In this study, we demonstrated for the first time that metformin administration alleviated bone loss in postmenopausal women and ovariectomized mice, based on reduced bone resorption markers, increased bone mineral density (BMD) and improvement of bone microstructure. Then, osteoclast precursors administered metformin in vitro and in vivo were collected to examine the differentiation potential and autophagical level. The mechanism was investigated by infection with lentivirus-mediated BNIP3 or E2F1 overexpression. We observed a dramatical inhibition of autophagosome synthesis and osteoclast formation and activity. Treatment with RAPA, an autophagy activator, abrogated the metformin-mediated autophagy downregulation and inhibition of osteoclastogenesis. Additionally, overexpression of E2F1 demonstrated that reduction of OVX-upregulated autophagy mediated by metformin was E2F1 dependent. Mechanistically, metformin-mediated downregulation of E2F1 in ovariectomized mice could downregulate BECN1 and BNIP3 levels, which subsequently perturbed the binding of BECN1 to BCL2. Furthermore, the disconnect between BECN1 and BCL2 was shown by BNIP3 overexpression. CONCLUSION: In summary, we demonstrated the effect and underlying mechanism of metformin on OVX-induced bone loss, which could be, at least in part, ascribed to its role in downregulating autophagy during osteoclastogenesis via E2F1-dependent BECN1 and BCL2 downregulation, suggesting that metformin or E2F1 inhibitor is a potential agent against postmenopausal bone loss. Video abstract.

LncRNA KCNQ1OT1 accelerates fracture healing via modulating miR-701-3p/FGFR3 axis.

Emerging evidence highlights the role of the long noncoding RNA (lncRNA) KCNQ1OT1 in fracture healing. Osteoblast proliferation, migration, and survival are pivotal during this process. In this study, we aimed to improve our understanding of the regulatory role of lncRNA KCNQ1OT1 during osteoblast proliferation, migration, and survival. We searched the gene expression omnibus databases and LncBase Experimental V.2 to identify key microRNAs (miRNAs) targets of KCNQ1OT1. MiR-701-3p was selected as a differentially expressed miRNA and RNA immunoprecipitation assays were performed to verify its interaction with KCNQ1OT1. Fibroblast growth factor receptor 3 (FGFR3) was also identified as a target of miR-701-3p. We further identified KCNQ1OT1 as a competing endogenous RNA of miR-701-3p that could influence osteoblast proliferation, migration, and apoptosis in vitro and in vivo. Taken together, our results indicate that the KCNQ1OT1/miR-701-3p/FGFR3 axis is an important regulator of osteoblast proliferation, migration, and apoptosis, and provide a new therapeutic avenue for fracture healing.

Exosomes derived from pioglitazone-pretreated MSCs accelerate diabetic wound healing through enhancing angiogenesis.

BACKGROUND: Enhanced angiogenesis can promote diabetic wound healing. Mesenchymal stem cells (MSCs)-derived exosomes, which are cell-free therapeutics, are promising candidates for the treatment of diabetic wound healing. The present study aimed to investigate the effect of exosomes derived from MSCs pretreated with pioglitazone (PGZ-Exos) on diabetic wound healing. RESULTS: We isolated PGZ-Exos from the supernatants of pioglitazone-treated BMSCs and found that PGZ-Exos significantly promote the cell viability and proliferation of Human Umbilical Vein Vascular Endothelial Cells (HUVECs) injured by high glucose (HG). PGZ-Exos enhanced the biological functions of HUVECs, including migration, tube formation, wound repair and VEGF expression in vitro. In addition, PGZ-Exos promoted the protein expression of p-AKT, p-PI3K and p-eNOS and suppressed that of PTEN. LY294002 inhibited the biological function of HUVECs through inhibition of the PI3K/AKT/eNOS pathway. In vivo modeling in diabetic rat wounds showed that pioglitazone pretreatment enhanced the therapeutic efficacy of MSCs-derived exosomes and accelerated diabetic wound healing via enhanced angiogenesis. In addition, PGZ-Exos promoted collagen deposition, ECM remodeling and VEGF and CD31 expression, indicating adequate angiogenesis in diabetic wound healing. CONCLUSIONS: PGZ-Exos accelerated diabetic wound healing by promoting the angiogenic function of HUVECs through activation of the PI3K/AKT/eNOS pathway. This offers a promising novel cell-free therapy for treating diabetic wound healing.

A Novel Instant 3-Dimensional Printing System for Postoperative Fracture Patients: A Comparative Cohort Study.

BACKGROUND Traditional plaster (TP) is a widely used auxiliary fixation (AF) approach for postoperative fracture patients. However, patient discomfort and inconvenience to clinicians has limited its application. We introduce a novel instant 3-dimensional printing appliance system (3D-AS) to address such issues. MATERIAL AND METHODS Twenty-seven postoperative fracture patients were divided randomly between a TP group and a 3D-AS group, and analyzed retrospectively. Radiographic images during follow-up were evaluated for fracture healing and fracture reduction quality. The range of motion (ROM) was recorded to assess motor performance. Patient pain was assessed using the Visual Analogue Scale (VAS). Complications were also compared between the 2 groups. RESULTS The patients comprised 17 men and 10 women with ages ranging from 21 to 69 years (mean age: 47.35). All patients completed a follow-up visit (range: 14-19 months, mean: 13.59 months). Although no significant difference was found between general characteristics (P>0.05) and the time of fracture union (P>0.05), significant differences between groups were seen in complications (P<0.05), VAS (P<0.01), patient satisfaction (P<0.05), and ROM for the upper joints (P<0.05). CONCLUSIONS Our study suggests that 3D-AS provides better upper-limb ROM and more comfortable healing for postoperative fracture patients, indicating that it can be recommended for use in such patients.

Methyltransferase-like 3-mediated N6-methyladenosine modification of miR-7212-5p drives osteoblast differentiation and fracture healing.

N6-methyladenosine (m6A) modification has been reported in various diseases and implicated in increasing numbers of biological processes. However, previous studies have not focused on the role of m6A modification in fracture healing. Here, we demonstrated that m6A modifications are decreased during fracture healing and that methyltransferase-like 3 (METTL3) is the main factor involved in the abnormal changes in m6A modifications. Down-regulation of METTL3 promotes osteogenic processes both in vitro and in vivo, and this effect is recapitulated by the suppression of miR-7212-5p maturation. Further studies have shown that miR-7212-5p inhibits osteoblast differentiation in MC3T3-E1 cells by targeting FGFR3. The present study demonstrated an important role of the METTL3/miR-7212-5p/FGFR3 axis and provided new insights on m6A modification in fracture healing.

IL-10 induces MC3T3-E1 cells differentiation towards osteoblastic fate in murine model.

Interleukin-10 (IL-10) displays well-documented anti-inflammatory effects, but its effects on osteoblast differentiation have not been investigated. In this study, we found IL-10 negatively regulates microRNA-7025-5p (miR-7025-5p), the down-regulation of which enhances osteoblast differentiation. Furthermore, through luciferase reporter assays, we found evidence that insulin-like growth factor 1 receptor (IGF1R) is a miR-7025-5p target gene that positively regulates osteoblast differentiation. In vivo studies indicated that the pre-injection of IL-10 leads to increased bone formation, while agomiR-7025-5p injection delays fracture healing. Taken together, these results indicate that IL-10 induces osteoblast differentiation via regulation of the miR-7025-5p/IGF1R axis. IL-10 therefore represents a promising therapeutic strategy to promote fracture healing.

Circulating Exosomal miR-20b-5p Inhibition Restores Wnt9b Signaling and Reverses Diabetes-Associated Impaired Wound Healing.

At present, developing therapeutic strategies to improve wound healing in individuals with diabetes remains challenging. Exosomes represent a promising nanomaterial from which microRNAs (miRNAs) can be isolated. These miRNAs have the potential to exert therapeutic effects, and thus, determining the potential therapeutic contributions of specific miRNAs circulating in exosomes is of great importance. In the present study, circulating exosomal miRNAs are identified in diabetic patients and assessed for their roles in the context of diabetic wound healing. A significant upregulation of miR-20b-5p is observed in exosomes isolated from patients with type 2 diabetes mellitus (T2DM), and this miRNA is able to suppress human umbilical vein endothelial cell angiogenesis via regulation of Wnt9b/ß-catenin signaling. It is found that the application of either miR-20b-5p or diabetic exosomes to wound sites is sufficient to slow wound healing and angiogenesis. In diabetic mice, it is found that knocking out miR-20b-5p significantly enhances wound healing and promotes wound angiogenesis. Together, these findings thus provide strong evidence that miR-20b-5p is highly enriched in exosomes from patients with T2DM and can be transferred to cells of the vascular endothelium, where it targets Wnt9b signaling to negatively regulate cell functionality and angiogenesis.

Saliva exosomes-derived UBE2O mRNA promotes angiogenesis in cutaneous wounds by targeting SMAD6.

BACKGROUND: Enhancing angiogenesis is critical for accelerating wound healing. Application of different types of exosomes (Exos) to promote angiogenesis represents a novel strategy for enhanced wound repair. Saliva is known to accelerate wound healing, but the underlying mechanisms remain unclear. RESULTS: Our results have demonstrated that saliva-derived exosomes (saliva-Exos) induce human umbilical vein endothelial cells (HUVEC) proliferation, migration, and angiogenesis in vitro, and promote cutaneous wound healing in vivo. Further experiments documented that Ubiquitin-conjugating enzyme E2O (UBE2O) is one of the main mRNAs of saliva-Exos, and activation of UBE2O has effects similar to those of saliva-Exos, both in vitro and in vivo. Mechanistically, UBE2O decreases the level of SMAD family member 6 (SMAD6), thereby activating bone morphogenetic protein 2 (BMP2), which, in turn, induces angiogenesis. CONCLUSIONS: The present work suggests that administration of saliva-Exos and UBE2O represents a promising strategy for enhancing wound healing through promotion of angiogenesis.

M2 Macrophagy-derived exosomal miRNA-5106 induces bone mesenchymal stem cells towards osteoblastic fate by targeting salt-inducible kinase 2 and 3.

BACKGROUND: Osteoblast differentiation is a vital process for fracture healing, and exosomes are nanosized membrane vesicles that can deliver therapeutic drugs easily and safely. Macrophages participate in the regulation of various biological processes in vivo, and macrophage-derived exosomes (MD-Exos) have recently been a topic of increasing research interest. However, few study has explored the link between MD-Exos and osteoblast differentiation. Herein, we sought to identify miRNAs differentially expressed between M1 and M2 macrophage-derived exosomes, and to evaluate their roles in the context of osteoblast differentiation. RESULTS: We found that microRNA-5106 (miR-5106) was significantly overexpressed in M2 macrophage-derived exosomes (M2D-Exos), while its expression was decreased in M1 macrophage-derived exosomes (M1D-Exos), and we found that this exosomal miRNA can induce bone mesenchymal stem cell (BMSC) osteogenic differentiation via directly targeting the Salt-inducible kinase 2 and 3 (SIK2 and SIK3) genes. In addition, the local injection of both a miR-5106 agonist or M2D-Exos to fracture sites was sufficient to accelerate healing in vivo. CONCLUSIONS: Our study demonstrates that miR-5106 is highly enriched in M2D-Exos, and that it can be transferred to BMSCs wherein it targets SIK2 and SIK3 genes to promote osteoblast differentiation.

Fibular Neck Osteotomy Approach in Treatment of Posterolateral Tibial Plateau Fractures: A Retrospective Case Series.

BACKGROUND The surgical strategies for posterolateral tibial plateau fractures are still inconsistent. Although a number of operative approaches were previously reported for surgical treatment of fractures of the posterolateral column in the tibial plateau, some approaches fail to provide direct visualization of the articular surface and do not allow enough space to access the posterolateral area of the lateral tibial plateau, thereby leading to unsatisfactory reconstruction of the knee and poor articular activity. MATERIAL AND METHODS We retrospectively reviewed records of 21 patients who underwent fibular neck osteotomy approach for posterolateral fractures. Radiographs taken during follow-up were used to evaluate the quality of fracture reduction and lower-limb axis. The Tegner-Lysholm score was used to assess patient functional performance. Complications, including incision infection, osteotomy nonunion, peroneal nerve injury, and fragment displacement, were evaluated. RESULTS We included 12 males and 9 females, with an age range of 27-67 years (mean age, 42.43 years). No intraoperative complications or postoperative complications were found. The mean operative duration was 128.05 min (range: 86-167 min). No patients were lost to clinical or radiographic follow-up. All patients had complete follow-up (range: 13-28 months, mean: 19.57 months). Anatomical fracture reduction was achieved in 14 patients. Radiological limb alignment was restored in all patients. The mean Tegner-Lysholm score was 87.07 (range: 74-95) and the average knee society score (KSS) was 91.67 (range: 86-94) at the final follow-up. CONCLUSIONS In this retrospective study, the results suggest that the fibular neck osteotomy approach is a good choice for treatment of posterolateral tibial plateau fractures.

In Situ Triggered Self-Contraction Bioactive Microgel Assembly Accelerates Diabetic Skin Wound Healing by Activating Mechanotransduction and Biochemical Pathway.

Chronic nonhealing skin wounds, characterized by reduced tissue contractility and inhibited wound cell survival under hyperglycemia and hypoxia, present a significant challenge in diabetic care. Here, an advanced self-contraction bioactive core-shell microgel assembly with robust tissue-adhesion (SMART-EXO) is introduced to expedite diabetic wound healing. The SMART-EXO dressing exhibits strong, reversible adhesion to damaged tissue due to abundant hydrogen and dynamic coordination bonds. Additionally, the core-shell microgel components and dynamic coordination bonds provide moderate rigidity, customizable self-contraction, and an interlinked porous architecture. The triggered in situ self-contraction of the SMART-EXO dressing enables active, tunable wound contraction, activating mechanotransduction in the skin and promoting the optimal fibroblast-to-myofibroblast conversion, collagen synthesis, and angiogenesis. Concurrently, the triggered contraction of SMART-EXO facilitates efficient loading and on-demand release of bioactive exosomes, contributing to re-epithelialization and wound microenvironment regulation in diabetic mice. RNA-seq results reveal the activation of critical signaling pathways associated with mechanosensing and exosome regulation, highlighting the combined biomechanical and biochemical mechanisms. These findings underscore SMART-EXO as a versatile, adaptable solution to the complex challenges of diabetic wound care.

Research progress of gene therapy combined with tissue engineering to promote bone regeneration.

Gene therapy has emerged as a highly promising strategy for the clinical treatment of large segmental bone defects and non-union fractures, which is a common clinical need. Meanwhile, many preclinical data have demonstrated that gene and cell therapies combined with optimal scaffold biomaterials could be used to solve these tough issues. Bone tissue engineering, an interdisciplinary field combining cells, biomaterials, and molecules with stimulatory capability, provides promising alternatives to enhance bone regeneration. To deliver and localize growth factors and associated intracellular signaling components into the defect site, gene therapy strategies combined with bioengineering could achieve a uniform distribution and sustained release to ensure mesenchymal stem cell osteogenesis. In this review, we will describe the process and cell molecular changes during normal fracture healing, followed by the advantages and disadvantages of various gene therapy vectors combined with bone tissue engineering. The growth factors and other bioactive peptides in bone regeneration will be particularly discussed. Finally, gene-activated biomaterials for bone regeneration will be illustrated through a description of characteristics and synthetic methods.

Exploring the anti-ferroptosis mechanism of Kai-Xin-San against Alzheimer's disease through integrating network pharmacology, bioinformatics, and experimental validation strategy in vivo and in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Kai Xin San (KXS), first proposed by Sun Simiao during the Tang Dynasty, has been utilized to treat dementia by tonifying qi and dispersing phlegm. AIM OF THE STUDY: This study aimed to elucidate the mechanism by which KXS exerts its therapeutic effects on Alzheimer's disease (AD) by targeting ferroptosis, using a combination of network pharmacology, bioinformatics, and experimental validation strategies. MATERIALS AND METHODS: The active target sites and the further potential mechanisms of KXS in protecting against AD were investigated through molecular docking, molecular dynamics simulation, and network pharmacology, and combined with the validation of animal experiments. RESULTS: Computational and experimental findings provide the first indication that KXS significantly improves learning and memory defects and inhibits neuronal ferroptosis by repairing mitochondria damage and upregulating the protein expression of ferroptosis suppressor protein 1 (FSP1) in vivo APP/PS1 mice AD model. According to bioinformatics analysis, the mechanism by which KXS inhibits ferroptosis may involve SIRT1. KXS notably upregulated the mRNA and protein expression of SIRT1 in both vivo APP/PS1 mice and in vitro APP-overexpressed HT22 cells. Additionally, KXS inhibited ferroptosis induced by APP-overexpression in HT22 cells through activating the SIRT1-FSP1 signal pathway. CONCLUSIONS: Collectively, our findings suggest that KXS may inhibit neuronal ferroptosis through activating the SIRT1/FSP1 signaling pathway. This study reveals the scientific basis and underlying modern theory of replenishing qi and eliminating phlegm, which involves the inhibition of ferroptosis. Moreover, it highlights the potential application of SIRT1 or FSP1 activators in the treatment of AD and other ferroptosis-related diseases.