Combining topical dermal infused exosomes with injected calcium hydroxylapatite for enhanced tissue biostimulation.

BACKGROUND: Exosome research continues to flourish. Subsequent knowledge surrounding indications, dose-response, safety, efficacy, and the ability to combine exosome treatment as a "skin primer"-for biostimulation modalities such as calcium hydroxylapatite (CaHA), platelet-rich plasma (PRP), and platelet-rich fibrin matrix (PRFM) is growing rapidly. The objective of this study was to develop safe, reproducible methods of improving topical exosome absorption to enhance the quality of skin either by themselves, or in combination with injectable CaHA. METHODS: Under IRB Approval (International Cell Surgical Society: ICSS-2022-007), 40 patients were enrolled in this study. Twenty patients underwent facial biostimulatory dermal infusion alone, to determine if this method allowed adequate exosome absorption. Five patients underwent facial biostimulatory infusion followed immediately by Dilute CaHA injection (1:1 dilution) to the face. Five patients underwent exosome biostimulatory dermal infusion followed immediately by hyperdilute CaHA (dilution 1:4) injection to the neck. Five patients underwent Facial Dilute CaHA injection (1:1 dilution) alone, without dermal infusion. Five patients underwent neck hyperdilute CaHA injection (1:4 dilution) alone, without dermal infusion. All patients had pretreatment Quantificare 3-D photo-documentation and skin analysis (Quantificare, France). In all patients, the skin was first cleansed with a gentle glycolic acid facial wash (Gregory MD). To induce a "homing inflammatory environment" for the exosomes, sea salt exfoliation was performed (SaltFacial®, SaltMed, Cardiff, CA). A nitric oxide-generating serum (N101 Pneuma Nitric Oxide, Austin, TX) was then applied to act as an enhanced vehicle for absorption. A 3 MHz ultrasound (SaltFacial®, SaltMed, Cardiff, CA) was then utilized to further deepen the absorption of the nitric oxide serum. A topical emulsion containing equal volumes (1.0 cc containing 1 million) of exosomes (Kimera Labs, Miramar, FL), 25 units of botulinum toxin (Xeomin, Merz Aesthetics, Raleigh, NC) and hyaluronic acid (Belatero, Merz Aesthetics, Raleigh, NC) was mixed via back-and-forth propulsion in a 3-cc syringe. When adequately mixed, the emulsion was then applied to the treatment areas. The cavitating ultrasound was then used to aid in the absorption of the emulsion. The patients were then treated with high-intensity LED therapy (SaltFacial®, SaltMed, Cardiff, CA), utilizing the collagen restoration preset program of combination red (660 nm) near-infrared (930 nm) wavelength for 20 min. Post-treatment Quantificare analysis was performed at 15 and 30 days after treatment. RESULTS: Without exception, all dermal infusion alone and CaHA injection alone patients showed an improvement in the tone, quality, and texture of their skin. Quantificare results showed consistent improvement in wrinkles, pores, skin evenness, improved vascularity, and a reduction in oiliness and unwanted pigment. When employed as a skin primer prior to injections (CaHA), enhanced and more rapid results were seen. CONCLUSIONS: Biostimulatory dermal infusion can be achieved utilizing topical placental mesenchymal stem cell-derived exosomes. These exosomes can be used alone, or mixed with ancillary ingredients such as botulinum toxin, hyaluronic acid dermal filler, and CaHA to customize and personalize treatments based upon individual patient needs. Topical absorption is enhanced with sea salt exfoliation, a topical nitric oxide-generating serum, and 3 MHz cavitating ultrasound. Post-absorption activity is enhanced with high-intensity LED treatment. The addition of CaHA injections after the topical exosome "priming of the skin" yielded enhanced skin quality faster than exosomes or CaHA alone.

Multifaceted applications of ulvan polysaccharides: Insights on biopharmaceutical avenues.

Ulvans are water-soluble sulfated polysaccharides predominantly found in the cell wall of green algae. They hold unique characteristics that are attributed to their 3D conformation, functional groups along with the presence of saccharides and sulfate ions. Traditionally, ulvans are widely used as food supplements and probiotics owing to the high content of carbohydrates. Despite their widespread usage in food industry, an in-depth understanding is required for extrapolating their potential application as a nutraceutical and medicinal agent which could be beneficial in promoting human health and well-being. This review emphasizes novel therapeutic avenues where ulvan polysaccharides can be used beyond their nutritional applications. A collection of literature points towards multifarious applications of ulvan in various biomedical fields. Structural aspects along with extraction and purification methods have been discussed. The underlying molecular mechanisms associated with its biomedical potential in different therapeutic fields like oncology, infectious diseases, inflammation, neuroprotection and tissue engineering, etc. have been unravelled. Challenges associated with clinical translation and future perspectives have been deliberated.

Development of an improved inhibitor of Lats kinases to promote regeneration of mammalian organs.

The Hippo signaling pathway acts as a brake on regeneration in many tissues. This cascade of kinases culminates in the phosphorylation of the transcriptional cofactors Yap and Taz, whose concentration in the nucleus consequently remains low. Various types of cellular signals can reduce phosphorylation, however, resulting in the accumulation of Yap and Taz in the nucleus and subsequently in mitosis. We earlier identified a small molecule, TRULI, that blocks the final kinases in the pathway, Lats1 and Lats2, and thus elicits proliferation of several cell types that are ordinarily postmitotic and aids regeneration in mammals. In the present study, we present the results of chemical modification of the original compound and demonstrate that a derivative, TDI-011536, is an effective blocker of Lats kinases in vitro at nanomolar concentrations. The compound fosters extensive proliferation in retinal organoids derived from human induced pluripotent stem cells. Intraperitoneal administration of the substance to mice suppresses Yap phosphorylation for several hours and induces transcriptional activation of Yap target genes in the heart, liver, and skin. Moreover, the compound initiates the proliferation of cardiomyocytes in adult mice following cardiac cryolesions. After further chemical refinement, related compounds might prove useful in protective and regenerative therapies.

Heterophyllin B, a cyclopeptide from Pseudostellaria heterophylla, improves memory via immunomodulation and neurite regeneration in i.c.v.Aß-induced mice.

Pseudostellaria heterophylla, has historically been used as medicine food homology plant for thousand years in China. Our previous studies had indicated that daily intake of Pseudostellaria heterophylla extract enhanced cognitive memory. Herein, heterophyllin B (HET-B), a brain permeable cyclopeptide from Pseudostellaria heterophylla was determined, and the molecular mechanism underlying its memory improvement effects was investigated. Pseudostellaria heterophylla extract as well as HET-B reversed Aß25-35-induced axonal atrophy and neuronal apoptosis in cultured cortical neurons of mice. HET-B could enhance memory retrieval, modulate splenic T helper cell, and ameliorate neuroinflammation in i.c.v. Aß1-42 injected Alzheimer's disease (AD) mice. To explore the mechanism of action, network pharmacology was performed to predict protein targets and pathways of HET-B against AD. Five key targets were identified related to the effect of HET-B in AD intervention, and were clarified involved in axonal regeneration. We revealed for the first time that HET-B promoted memory retrieval through axonal regeneration and anti-neuroinflammation. This study provides a basis to research on HET-B as nutritional supplements for brain healthy.

LiCl-induced immunomodulatory periodontal regeneration via the activation of the Wnt/ß-catenin signaling pathway.

BACKGROUND: Growing evidence suggests that excessive inflammation hampers the regenerative capacity of periodontal ligament cells (PDLCs) and that activation of the Wnt/ß-catenin pathway is crucial in suppressing immune dysregulation. OBJECTIVE: This study aimed to establish the role of the Wnt/ß-catenin in regulating the immune microenvironment and its subsequent impact on periodontal regeneration. METHODS: Lithium chloride (LiCl, Wnt activator) was administered daily into the standard periodontal defects created in 12-week-old Lewis rats. Harvested at 1-week and 2-week post-surgery, samples were then subjected to histological and immunohistochemical evaluation of macrophage distribution and phenotype (pro-inflammatory M1 and anti-inflammatory M2). A murine macrophage cell line, RAW 264.7, was stimulated with LiCl to activate Wnt/ß-catenin. Following treatment with the conditioned medium derived from the LiCl-activated macrophages, the expression of bone- and cementum-related markers of the PDLCs was determined. The involvement of Wnt/ß-catenin in the immunoregulation and autophagic activity was further investigated with the addition of cardamonin, a commercially available Wnt inhibitor. RESULTS: A significantly increased number of macrophages were detected around the defects during early healing upon receiving the Wnt/ß-catenin signaling cue. The defect sites in week 2 exhibited fewer M1 and more M2 macrophages along with an enhanced regeneration of alveolar bone and cementum in the Wnt/ß-catenin activation group. LiCl-induced immunomodulatory effect was accompanied with the activation Wnt/ß-catenin signaling, which was suppressed in the presence of Wnt inhibitor. Exposure to LiCl could induce autophagy in a dose-dependent manner, thus maintaining macrophages in a regulatory state. The expression level of bone- and cementum-related markers was significantly elevated in PDLCs stimulated with LiCl-activated macrophages. CONCLUSION: The application of Wnt activator LiCl facilitates the recruitment of macrophages to defect sites and regulates their phenotypic switching in favor of periodontal regeneration. Suppression of Wnt/ß-catenin pathway could attenuate the LiCl-induced immunomodulatory effect. Taken together, the Wnt/ß-catenin pathway may be targeted for therapeutic interventions in periodontal diseases.

A sonication-induced silk-collagen hydrogel for functional cartilage regeneration.

Cartilage tissue has limited self-regeneration capacity and current treatment methods often result in fibrocartilage formation. Although collagen has shown the ability to induce chondrogenesis of mesenchymal stem cells (MSCs) and regenerate hyaline cartilage, the application of a pure collagen hydrogel is inherently limited by its fast degradation, poor mechanical properties and excessive cell-mediated shrinkage. To overcome this challenge, we developed a sonication-induced silk-collagen composite hydrogel (COL + SF(S)) and investigated its physicochemical and biological properties compared with a collagen hydrogel (COL) and a non-sonicated silk-collagen composite hydrogel (COL + SF(NS)). The results showed that the sonication treatment of silk fibroin induced antiparallel ß-sheet formation and a stronger negative charge on the silk fibroin molecule, which resulted in improved mechanical properties of the COL + SF(S) hydrogel. The COL + SF(S) hydrogel exhibited superior stability during cell culture and promoted the gene expression of SOX9 at the early stage and sulfated glycosaminoglycan (sGAG) deposition without any exogenous growth factor. Moreover, the cartilage regeneration capacity of the COL + SF(S) group was evaluated in rabbit knee defects. The COL + SF(S) group exhibited well-integrated articular hyaline cartilage closely resembling native articular cartilage after 6 months. Overall, the COL + SF(S) hydrogel holds great potential as a scaffold material to regenerate functional hyaline cartilage.

Xenopus laevis il11ra.L is an experimentally proven interleukin-11 receptor component that is required for tadpole tail regeneration.

Xenopus laevis tadpoles possess high regenerative ability and can regenerate functional tails after amputation. An early event in regeneration is the induction of undifferentiated cells that form the regenerated tail. We previously reported that interleukin-11 (il11) is upregulated immediately after tail amputation to induce undifferentiated cells of different cell lineages, indicating a key role of il11 in initiating tail regeneration. As Il11 is a secretory factor, Il11 receptor-expressing cells are thought to mediate its function. X. laevis has a gene annotated as interleukin 11 receptor subunit alpha on chromosome 1L (il11ra.L), a putative subunit of the Il11 receptor complex, but its function has not been investigated. Here, we show that nuclear localization of phosphorylated Stat3 induced by Il11 is abolished in il11ra.L knocked-out culture cells, strongly suggesting that il11ra.L encodes an Il11 receptor component. Moreover, knockdown of il11ra.L impaired tadpole tail regeneration, suggesting its indispensable role in tail regeneration. We also provide a model showing that Il11 functions via il11ra.L-expressing cells in a non-cell autonomous manner. These results highlight the importance of il11ra.L-expressing cells in tail regeneration.

Peptide OM-LV20 promotes structural and functional recovery of spinal cord injury in rats.

At present, there are no satisfactory therapeutic drugs for the functional recovery of spinal cord injury (SCI). We previously identified a novel peptide (OM-LV20) that accelerated the regeneration of injured skin tissues of mice and exerts neuroprotective effects against cerebral ischemia/reperfusion injury in rats. Here, the intraperitoneal injection of OM-LV20 (1 µg/kg) markedly improved motor function recovery in the hind limbs of rats with traumatic SCI, and further enhanced spinal cord repair. Administration of OM-LV20 increased the number of surviving neuron bodies, as well as the expression levels of brain-derived neurotrophic factor (BDNF) and its receptor tyrosine receptor kinase B (TrkB). In the acute stage of SCI, OM-LV20 treatment also increased superoxide dismutase and glutathione content but decreased the levels of malonaldehyde and nitric oxide. Thus, OM-LV20 significantly promoted structural and functional recovery of SCI in adult rats by increasing neuronal survival and BDNF and TrkB expression, and thereby regulating the balance of oxidative stress. Based on our knowledge, this research is the first report on the effects of amphibian-derived peptide on the recovery of SCI and our results highlight the potential of peptide OM-LV20 administration in the acceleration of the recovery of SCI.

CoQ10 enhances the efficacy of airway basal stem cell transplantation on bleomycin-induced idiopathic pulmonary fibrosis in mice.

BACKGROUND: Recent studies have demonstrated that airway basal stem cells (BCs) transplantation can ameliorate bleomycin-induced idiopathic pulmonary fibrosis (IPF) through lung regeneration promotion. However, BCs under oxidative stress in the alveolar microenvironment are poor in survival, causing unsatisfied efficacy of BCs transplantation. In this study, we investigated whether Coenzyme Q10(CoQ10) counteracts oxidative stress in the alveolar microenvironment, thus improved the efficacy of BCs transplantation for IPF treatment. METHODS: The protective effects of CoQ10 on H2O2-induced BCs apoptosis and cytoplasmic reactive oxygen species (ROS) level were tested by flow cytometry in vitro. The therapeutic effects of BCs combined with CoQ10 were compared to a single BCs transplantation protocol in IPF treatment after 2 weeks and were evaluated by parameters including changes of body weight and survival rate, as well as various levels of pulmonary inflammation, α-SMA expression and hydroxyproline (HYP) in IPF mouse lung tissues. RESULTS: CoQ10 preincubation with BCs (10 mM, 24 h) significantly reduced the late apoptosis of BCs and the number of oxidative stressful BCs as a result of H2O2 stimulation (1 mM, 6 h) in vitro. IPF mouse model was constructed through bleomycin (5 mg/kg) intratracheal instillation. Bleomycin-induced IPF mice showed weight loss continuously and mortality increased progressively during modeling. Serious pulmonary inflammatory cell infiltration, collagen fiber proliferation, and collagen protein deposition were observed in lung tissues of IPF mice. Though BCs transplantation alone improved indicators above in bleomycin-induced IPF mice to some extent, the combination with CoQ10 improved the transplantation efficacy and obtained better therapeutic effects. CONCLUSION: CoQ10 blocked H2O2-induced apoptosis of BCs and ROS production in vitro, and enhanced the efficacy of BCs transplantation against bleomycin-induced IPF in mice.

In vitro evaluation of injectable Tideglusib-loaded hyaluronic acid hydrogels incorporated with Rg1-loaded chitosan microspheres for vital pulp regeneration.

Injectable systems receive attention in endodontics due to the complicated and irregular anatomical structure of root canals. Here, injectable Tideglusib (Td)-loaded hyaluronic acid hydrogels (HAH) incorporated with Rg1-loaded chitosan microspheres (CSM) were developed for vital pulp regeneration, providing release of Td and Rg1 to trigger odontoblastic differentiation of human dental pulp stem cells (DPSC) by Td and vascularization of pulp by Rg1. The optimal concentrations were determined as 90 nM and 50 µg/mL for Td and Rg1, and loaded in HA and CSM in HAH, respectively. Odontogenic (COL1A1, ALP, OCN, Axin-2, DSPP, and DMP1) and angiogenic (VEGFA, VEGFR2, and eNOS) differentiation of DPSC cultured in the presence of hydrogels was shown at gene expression level. Our results suggest that our injectable hydrogel formulation has potential to improve strategies for vital pulp regeneration. In vivo evaluations are needed to test the feasibility and potential of these hydrogels for vital pulp regeneration.

In situ graphene oxide-gelatin hydrogels with enhanced mechanical property for tissue adhesive and regeneration.

Extracellular matrix (ECM) is playing a critical role which is component of mammalian tissue that provide structural support to cells. In addition, ECM act as a local depot for growth factors that control cell phenotype and differentiation. In this regard, scaffold that mimicking the ECM structure is important to growth or wound healing process. Gelatin is natural polymer and derived from collagen which is a major component of ECM. Using gelatin as an ECM mimicking structure has advantage of providing three-dimensional growth or supporting to regulate the cell behavior, proliferation, migration, cell survival, and differentiation. In this study, we developed enzyme-mediated crosslinking gelatin-based hydrogels with robust mechanical property to mimicking ECM and effectively attach to the surrounding tissue with high adhesive property. The effect of different concentration of graphene oxide (GO) on the physico-chemical properties of gelatin hydrogels were investigated, particularly tissue adhesion strength. In vitro proteolytic degradation behavior and human dermal fibroblast proliferation study confirmed the hydrogels were biodegradable and promote cell proliferation. Overall, we suggest that GO incorporated gelatin hydrogels with additional interfacial interactions, showing a promising potential as an injectable tissue adhesive.

The Regenerative Potential of Substance P.

Wound healing is a highly coordinated process which leads to the repair and regeneration of damaged tissue. Still, numerous diseases such as diabetes, venous insufficiencies or autoimmune diseases could disturb proper wound healing and lead to chronic and non-healing wounds, which are still a great challenge for medicine. For many years, research has been carried out on finding new therapeutics which improve the healing of chronic wounds. One of the most extensively studied active substances that has been widely tested in the treatment of different types of wounds was Substance P (SP). SP is one of the main neuropeptides released by nervous fibers in responses to injury. This review provides a thorough overview of the application of SP in different types of wound models and assesses its efficacy in wound healing.

PLGA-collagen-BPNS Bifunctional composite mesh for photothermal therapy of melanoma and skin tissue engineering.

The treatment of melanoma requires not only the elimination of skin cancer cells but also skin regeneration to heal defects. To achieve this goal, a bifunctional composite scaffold of poly(DL-lactic-co-glycolic acid) (PLGA), collagen and black phosphorus nanosheets (BPNSs) was prepared by hybridizing a BPNS-embedded collagen sponge with a PLGA knitted mesh. The composite mesh increased the temperature under near-infrared laser irradiation. The incorporation of BPNSs provided the PLGA-collagen-BPNS composite mesh with excellent photothermal properties for the photothermal ablation of melanoma cells both in vitro and in vivo. The PLGA-collagen-BPNS composite mesh had high mechanical strength for easy handling. The PLGA-collagen-BPNS composite mesh facilitated the proliferation of fibroblasts, promoted the expression of angiogenesis-related genes and the genes of components of the extracellular matrix for skin tissue regeneration. The high mechanical strength, photothermal ablation capability and skin tissue regeneration effects demonstrate that the bifunctional PLGA-collagen-BPNS composite mesh is a versatile and effective platform for the treatment of melanoma and the regeneration of skin defects.

Evaluating potential of tissue-engineered cryogels and chondrocyte derived exosomes in articular cartilage repair.

Treatment of articular cartilage injuries especially osteochondral tissue requires intervention of bioengineered scaffold. In this study, we investigated the potential of the tissue-engineered cryogel scaffold fabricated using cryogelation technology. Two types of cryogels viz. chitosan-gelatin-chondroitin sulfate (CGC) for articular cartilage and nano-hydroxyapatite-gelatin (HG) for subchondral bone were fabricated. Further, novel bilayer cryogel designed using single process fabrication of two layers (CGC as top layer and HG as the lower layer) was designed to mimic osteochondral unit. CGC cryogel was tested for their biocompatibility using the enzymatically isolated chondrcoytes from goat articular cartilage while HG cryogel was tested using pre-osteoblast cell line. Extracellular vesicles, specifically exosomes were isolated from the spent media of chondrocytes to validate their effect over cell proliferation and migration which are required for defect healing and infiltration respectively. These isolated exosomes were characterized and analyzed for confirming their size distribution profile and visualized morphologically using advanced microscopy techniques. For cartilage part, CGC cryogels were examined as delivery system for delivering exosomes at defect site, where 80% of release was observed in 72 h. Release of 18.7 µg chondroitin sulfate/mg cryogel was obtained in a period of one week from CGC cryogel (termed cryogel extract) which has chondroprotective effect. Further, effect of exosome concentration (10 and 20 µg/ml), CGC extract and combination of exosome and CGC extract (Exo-Ex) were assessed over the chondrocytes. In addition, in vitro scratch wound assay was performed to analyse the migration capacity over the micro-injury when treated with exosomes, cryogel extract and Exo-Ex. The overall results thus answer key questions of therapeutic potential of chondrocyte exosomes, cryogel extract in addition to potential of CGC and HG cryogel for osteochondral repair.

Dendrimer-Functionalized Metal Oxide Nanoparticle-Mediated Self-Assembled Collagen Scaffold for Skin Regenerative Application: Function of Metal in Metal Oxides.

Functionalized metal oxide nanoparticles cross-linked collagen scaffolds are widely used in skin regenerative applications because of their enhanced physicochemical and biocompatibility properties. From the safety clinical trials point of view, there are no reports that have compared the effects of functionalized metal oxide nanoparticles mediated collagen scaffolds for in vivo skin regenerative applications. In this work, triethoxysilane-poly (amido amine) dendrimer generation 3 (TES-PAMAM-G3 or G3)-functionalized spherical shape metal oxide nanoparticles (MO NPs: ZnO, TiO2, Fe3O4, CeO2, and SiO2, size: 12-25 nm) cross-linked collagen scaffolds were prepared by using a self-assembly method. Triple helical conformation, pore size, mechanical strength, and in vitro cell viability of MO-TES-PAMAM-G3-collagen scaffolds were studied through different methods. The in vivo skin regenerative proficiency of MO-TES-PAMAM-G3-collagen scaffolds was analyzed by implanting the scaffold on wounds in Wistar albino rats. The results demonstrated that MO-TES-PAMAM-G3-collagen scaffold showed superior skin regeneration properties than other scaffolds. The skin regenerative efficiency of MO NPs followed the order ZnO > TiO2 > CeO2 > SiO2 > Fe3O4 NPs. This result can be attributed to higher mechanical strength, cell viability, and better antibacterial activity of ZnO-TES-PAMAM-G3-collagen scaffold that leads to accelerate the skin regenerative properties in comparison to other metal oxide based collagen scaffolds.

Selective Cdk9 inhibition resolves neutrophilic inflammation and enhances cardiac regeneration in larval zebrafish.

Sustained neutrophilic inflammation is detrimental for cardiac repair and associated with adverse outcomes following myocardial infarction (MI). An attractive therapeutic strategy to treat MI is to reduce or remove infiltrating neutrophils to promote downstream reparative mechanisms. CDK9 inhibitor compounds enhance the resolution of neutrophilic inflammation; however, their effects on cardiac repair/regeneration are unknown. We have devised a cardiac injury model to investigate inflammatory and regenerative responses in larval zebrafish using heartbeat-synchronised light-sheet fluorescence microscopy. We used this model to test two clinically approved CDK9 inhibitors, AT7519 and flavopiridol, examining their effects on neutrophils, macrophages and cardiomyocyte regeneration. We found that AT7519 and flavopiridol resolve neutrophil infiltration by inducing reverse migration from the cardiac lesion. Although continuous exposure to AT7519 or flavopiridol caused adverse phenotypes, transient treatment accelerated neutrophil resolution while avoiding these effects. Transient treatment with AT7519, but not flavopiridol, augmented wound-associated macrophage polarisation, which enhanced macrophage-dependent cardiomyocyte number expansion and the rate of myocardial wound closure. Using cdk9-/- knockout mutants, we showed that AT7519 is a selective CDK9 inhibitor, revealing the potential of such treatments to promote cardiac repair/regeneration.

Indoleamine 2, 3 Dioxygenase 1 Impairs Chondrogenic Differentiation of Mesenchymal Stem Cells in the Joint of Osteoarthritis Mice Model.

Osteoarthritis (OA) is a serious joint inflammation that leads to cartilage degeneration and joint dysfunction. Mesenchymal stem cells (MSCs) are used as a cell-based therapy that showed promising results in promoting cartilage repair. However, recent studies and clinical trials explored unsatisfied outcomes because of slow chondrogenic differentiation and increased calcification without clear reasons. Here, we report that the overexpression of indoleamine 2,3 dioxygenase 1 (IDO1) in the synovial fluid of OA patients impairs chondrogenic differentiation of MSCs in the joint of the OA mice model. The effect of MSCs mixed with IDO1 inhibitor on the cartilage regeneration was tested compared to MSCs mixed with IDO1 in the OA animal model. Further, the mechanism exploring the effect of IDO1 on chondrogenic differentiation was investigated. Subsequently, miRNA transcriptome sequencing was performed for MSCs cocultured with IDO1, and then TargetScan was used to verify the target of miR-122-5p in the SF-MSCs. Interestingly, we found that MSCs mixed with IDO1 inhibitor showed a significant performance to promote cartilage regeneration in the OA animal model, while MSCs mixed with IDO1 failed to stimulate cartilage regeneration. Importantly, the overexpression of IDO1 showed significant inhibition to Sox9 and Collagen type II (COL2A1) through activating the expression of ß-catenin, since inhibiting of IDO1 significantly promoted chondrogenic signaling of MSCs (Sox9, COL2A1, Aggrecan). Further, miRNA transcriptome sequencing of SF-MSCs that treated with IDO1 showed significant downregulation of miR-122-5p which perfectly targets Wnt1. The expression of Wnt1 was noticed high when IDO1 was overexpressed. In summary, our results suggest that IDO1 overexpression in the synovial fluid of OA patients impairs chondrogenic differentiation of MSCs and cartilage regeneration through downregulation of miR-122-5p that activates the Wnt1/ß-catenin pathway.

Challenge Tooth Regeneration in Adult Dogs with Dental Pulp Stem Cells on 3D-Printed Hydroxyapatite/Polylactic Acid Scaffolds.

Tooth regeneration is an important issue. The purpose of this study was to explore the feasibility of using adult dental pulp stem cells on polylactic acid scaffolds for tooth regeneration. Three teeth were extracted from each side of the lower jaws of two adult dogs. In the experimental group, dental pulp stem cells were isolated and seeded in the 3D-printed hydroxyapatite/polylactic acid (HA/PLA) scaffolds for transplantation into left lower jaw of each dog. The right-side jaw of each dog was transplanted with cell-free scaffolds as the control group. Polychrome sequentially labeling was performed for observation of mineralization. Dental cone beam computed tomography (CBCT) irradiation was used for assessment. Nine months after surgery, dogs were euthanized, and the lower jaws of dogs were sectioned and fixed for histological observation with hematoxylin and eosin staining. The results showed that the degree of mineralization in the experimental group with cells seeded in the scaffolds was significantly higher than that of the control group transplanted with cell-free scaffolds. However, the HA/PLA scaffolds were not completely absorbed in both groups. It is concluded that dental pulp stem cells are important for the mineralization of tooth regeneration. A more rapid absorbable material was required for scaffold design for tooth regeneration.

Pharmacology active microcarriers delivering HGF associated with extracellular vesicles for myocardial repair.

Despite the curative approaches developed against myocardial infarction, cardiac cell death causes dysfunctional heart contractions that depend on the extent of the ischemic area and the reperfusion period. Cardiac regeneration may allow neovascularization and limit the ventricular remodeling caused by the scar tissue. We have previously found that large extracellular vesicles, carrying Sonic Hedgehog (lEVs), displayed proangiogenic and antioxidant properties, and decreased myocardial infarction size when administrated by intravenous injection. We propose to associate lEVs with pharmacology active microcarriers (PAMs) to obtain a combined cardioprotective and regenerative action when administrated by intracardiac injection. PAMs made of poly-D,L-lactic-coglycolic acid-poloxamer 188-poly-D,L-lactic-coglycolic acid and covered by fibronectin/poly-D-lysine provided a biodegradable and biocompatible 3D biomimetic support for the lEVs. When compared with lEVs alone, lEVs-PAMs constructs possessed an enhanced in vitro pro-angiogenic ability. PAMs were designed to continuously release encapsulated hepatocyte growth factor (PAMsHGF) and thus, locally increase the activity of the lEVs by the combined anti-fibrotic properties and regenerative properties. Intracardiac administration of either lEVs alone or lEVs-PAMsHGF improved cardiac function in a similar manner, in a rat model of ischemia-reperfusion. Moreover, lEVs alone or the IEVs-PAMsHGF induced arteriogenesis, but only the latter reduced tissue fibrosis. Taken together, these results highlight a promising approach for lEVs-PAMsHGF in regenerative medicine for myocardial infarction.

Cisd2 plays an essential role in corneal epithelial regeneration.

BACKGROUND: Age-related changes affecting the ocular surface cause vision loss in the elderly. Cisd2 deficiency drives premature aging in mice as well as resulting in various ocular surface abnormalities. Here we investigate the role of CISD2 in corneal health and disease. METHODS: We studied the molecular mechanism underlying the ocular phenotypes brought about by Cisd2 deficiency using both Cisd2 knockout (KO) mice and a human corneal epithelial cell (HCEC) cell line carrying a CRISPR-mediated CISD2KO background. We also develop a potential therapeutic strategy that targets the Ca2+ signaling pathway, which has been found to be dysregulated in the corneal epithelium of subjects with ocular surface disease in order to extend the mechanistic findings into a translational application. FINDINGS: Firstly, in patients with corneal epithelial disease, CISD2 is down-regulated in their corneal epithelial cells. Secondly, using mouse cornea, Cisd2 deficiency causes a cycle of chronic injury and persistent repair resulting in exhaustion of the limbal progenitor cells. Thirdly, in human corneal epithelial cells, CISD2 deficiency disrupts intracellular Ca2+ homeostasis, impairing mitochondrial function, thereby retarding corneal repair. Fourthly, cyclosporine A and EDTA facilitate corneal epithelial wound healing in Cisd2 knockout mice. Finally, cyclosporine A treatment restores corneal epithelial erosion in patients with dry eye disease, which affects the ocular surface. INTERPRETATION: These findings reveal that Cisd2 plays an essential role in the cornea and that Ca2+ signaling pathways are potential targets for developing therapeutics of corneal epithelial diseases. FUNDING: This study was supported by the Ministry of Science and Technology (MOST) and Chang Gung Medical Research Foundation, Taiwan.