Reconstructable Uterus-Derived Materials for Uterus Recovery toward Efficient Live Births

A Dopamine-Modified Hyaluronic Acid-Based Mucus Carrying Phytoestrogen and Urinary Exosome for Thin Endometrium Repair

Thin endometrium (TE) is closely associated with infertility in reproductive medicine. Estrogen therapy gains unsatisfactory outcomes. In this study, an artificial mucus based on dopamine (L-DOPA)-modified hyaluronic acid combining phytoestrogen cajaninstilbene acid and rat urinary exosomes (CUEHD) is constructed for TE treatment using a rat TE model. In the rat TE model, the dominant elastic behavior and adhesive properties of CUEHD guarantee adequate retention, rendering superior synergistic treatment efficacy and favorable biosafety characteristics. CUEHD treatment significantly increases endometrial thickness and promotes receptivity and fertility. Mechanistically, estrogen homeostasis, inflammation inhibition, and endometrial regeneration are achieved through the crosstalk between ER-NLRP3-IL1β and Wnt-β catenin-TGFβ-smad signaling pathways. Moreover, the therapeutic potential of exosomes from human urine and adipose tissue-derived stem cells (ADSCs) and rat ADSCs are also demonstrated, indicating extensive use of the artificial mucus system. Thus, this study illustrates a platform combining phytoestrogen and exosomes with promising implications for TE treatment.

Locationally activated PRP via an injectable dual-network hydrogel for endometrial regeneration

Enhancing the effectiveness of platelet-rich plasma (PRP) for endometrial regeneration is challenging, due to its limited mechanical properties and burst release of growth factors. Here, we proposed an injectable interpenetrating dual-network hydrogel that can locationally activate PRP within the uterine cavity, sustained release growth factors and further address the insufficient therapeutic efficacy. Locational activation of PRP is achieved using the dual-network hydrogel. The phenylboronic acid (PBA) modified methacrylated hyaluronic acid (HAMA) dispersion chelates Ca2+ by carboxy groups and polyphenol groups, and in situ crosslinked with PRP-loaded polyvinyl alcohol (PVA) dispersion by dynamic borate ester bonds thus establishing the soft hydrogel. Subsequently, in situ photo-crosslinking technology is employed to enhance the mechanical performance of hydrogels by initiating free radical polymerization of carbon-carbon double bonds to form a dense network. The PRP-hydrogel significantly promoted the endometrial cell proliferation, exhibited strong pro-angiogenic effects, and down-regulated the expression of collagen deposition genes by inhibiting the TGF-β1-SMAD2/3 pathway in vitro. In vivo experiments using a rat intrauterine adhesion (IUA) model showed that the PRP-hydrogel significantly promoted endometrial regeneration and restored uterine functionality. Furthermore, rats treated with the PRP-hydrogel displayed an increase in the number of embryos, litter size, and birth rate, which was similar to normal rats. Overall, this injectable interpenetrating dual-network hydrogel, capable of locational activation of PRP, suggests a new therapeutic approach for endometrial repair.

Injectable alginate-based zwitterionic hydrogels promoting endometrial repair and restoring fertility

The development of novel therapeutic approaches to facilitate endometrial repair and regeneration while preventing adhesion recurrence is a crucial research objective aimed at enhancing clinical outcomes for women with intrauterine adhesions (IUA). In this study, we introduced an injectable Alg-GMA/PTSB zwitterionic hydrogel, characterized by excellent biocompatibility, anti-protein adsorption properties, and biodegradability. In a rat model, the hydrogel significantly promoted the regeneration and angiogenesis of damaged endometrial tissue, leading to improved recovery of epithelial cells, glands, proliferation, and vascularization. Furthermore, it exhibited the ability to suppress cellular apoptosis and collagen deposition, thereby mitigating fibrosis. Additionally, the hydrogel restored the expression of estrogen/progesterone receptors and endometrial receptivity markers, contributing to enhanced embryo implantation and fertility. These findings underscore the potential of the hydrogel as a promising therapeutic strategy for addressing endometrial injury, reducing fibrosis, restoring fertility, and ultimately improving outcomes for women with IUA.

Ameliorating and refining islet organoids to illuminate treatment and pathogenesis of diabetes mellitus

Diabetes mellitus, a significant global public health challenge, severely impacts human health worldwide. The organoid, an innovative in vitro three-dimensional (3D) culture model, closely mimics tissues or organs in vivo. Insulin-secreting islet organoid, derived from stem cells induced in vitro with 3D structures, has emerged as a potential alternative for islet transplantation and as a possible disease model that mirrors the human body's in vivo environment, eliminating species difference. This technology has gained considerable attention for its potential in diabetes treatment. Despite advances, the process of stem cell differentiation into islet organoid and its cultivation demonstrates deficiencies, prompting ongoing efforts to develop more efficient differentiation protocols and 3D biomimetic materials. At present, the constructed islet organoid exhibit limitations in their composition, structure, and functionality when compared to natural islets. Consequently, further research is imperative to achieve a multi-tissue system composition and improved insulin secretion functionality in islet organoid, while addressing transplantation-related safety concerns, such as tumorigenicity, immune rejection, infection, and thrombosis. This review delves into the methodologies and strategies for constructing the islet organoid, its application in diabetes treatment, and the pivotal scientific challenges within organoid research, offering fresh perspectives for a deeper understanding of diabetes pathogenesis and the development of therapeutic interventions.

Cervical extracellular matrix hydrogel optimizes tumor heterogeneity of cervical squamous cell carcinoma organoids

Cervical cancer, primarily squamous cell carcinoma, is the most prevalent gynecologic malignancy. Organoids can mimic tumor development in vitro, but current Matrigel inaccurately replicates the tissue-specific microenvironment. This limitation compromises the accurate representation of tumor heterogeneity. We collected para-cancerous cervical tissues from patients diagnosed with cervical squamous cell carcinoma (CSCC) and prepared uterine cervix extracellular matrix (UCEM) hydrogels. Proteomic analysis of UCEM identified several tissue-specific signaling pathways including human papillomavirus, phosphatidylinositol 3-kinase-AKT, and extracellular matrix receptor. Secreted proteins like FLNA, MYH9, HSPA8, and EEF1A1 were present, indicating UCEM successfully maintained cervical proteins. UCEM provided a tailored microenvironment for CSCC organoids, enabling formation and growth while preserving tumorigenic potential. RNA sequencing showed UCEM-organoids exhibited greater similarity to native CSCC and reflected tumor heterogeneity by exhibiting CSCC-associated signaling pathways including virus protein-cytokine, nuclear factor κB, tumor necrosis factor, and oncogenes EGR1, FPR1, and IFI6. Moreover, UCEM-organoids developed chemotherapy resistance. Our research provides insights into advanced organoid technology through native matrix hydrogels.

Injectable "Homing-Like" Bioactive Short-Fibers for Endometrial Repair and Efficient Live Births

The prevalence of infertility caused by endometrial defects is steadily increasing, posing a significant challenge to women's reproductive health. In this study, injectable "homing-like" bioactive decellularized extracellular matrix short-fibers (DEFs) of porcine skin origin are innovatively designed for endometrial and fertility restoration. The DEFs can effectively bind to endometrial cells through noncovalent dipole interactions and release bioactive growth factors in situ. In vitro, the DEFs effectively attracted endometrial cells through the "homing-like" effect, enabling cell adhesion, spreading, and proliferation on their surface. Furthermore, the DEFs effectively facilitated the proliferation and angiogenesis of human primary endometrial stromal cells (HESCs) and human umbilical vein endothelial cells (HUVECs), and inhibited fibrosis of pretreated HESCs. In vivo, the DEFs significantly accelerated endometrial restoration, angiogenesis, and receptivity. Notably, the deposition of endometrial collagen decreased from 41.19 ± 2.16% to 14.15 ± 1.70% with DEFs treatment. Most importantly, in endometrium-injured rats, the use of DEFs increased the live birth rate from 30% to an impressive 90%, and the number and development of live births close to normal rats. The injectable "homing-like" bioactive DEFs system can achieve efficient live births and intrauterine injection of DEFs provides a new promising clinical strategy for endometrial factor infertility.

Minimally invasive delivery of human umbilical cord-derived mesenchymal stem cells by an injectable hydrogel via Diels-Alder click reaction for the treatment of intrauterine adhesions

Intrauterine adhesions (IUA) are the most common cause of uterine infertility, and conventional treatments have not consistently achieved satisfactory pregnancy rates. Stem cell therapy shows promising potential for the clinical treatment of IUA. Although various advanced biomaterials have been designed for delivering stem cells to the uterine cavity, there remain significant challenges, particularly in devising therapeutic strategies for clinical application that minimize surgical incisions and conform to the intricate structure of uterine cavity. Herein, an injectable hydrogel loaded with human umbilical cord-derived mesenchymal stem cells (UCMSCs) was synthesized via the Diels-Alder click reaction for endometrial regeneration and fertility restoration, exhibiting suitable mechanical properties, good biocompatibility, and desirable degradation properties. Notably, this hydrogel permitted minimally invasive administration and integrated seamlessly with surrounding tissue. Our study revealed that the UCMSCs-laden injectable hydrogel enhanced cell proliferation, migration, angiogenesis, and exhibited anti-fibrotic effects in vitro. The implantation of this hydrogel significantly facilitated endometrium regeneration and restored fertility in a rat endometrial damage model. Mechanistically, in vivo results indicated that the UCMSCs-laden injectable hydrogel effectively promoted macrophage recruitment and facilitated M2 phenotype polarization. Collectively, this hydrogel demonstrated efficacy in regenerating damaged endometrium, leading to the restoration of fertility. Consequently, it holds promise as a potential therapeutic strategy for endometrial damage and fertility decline arising from intrauterine adhesions. STATEMENT OF SIGNIFICANCE: Severe endometrial traumas frequently lead to intrauterine adhesions and subsequent infertility. Stem cell therapy shows promising potential for the clinical treatment of IUA; however, challenges remain, including low delivery efficiency and compromised stem cell activity during the delivery process. In this study, we fabricated an injectable hydrogel loaded with UCMSCs via the Diels-Alder click reaction, which exhibited unique bioorthogonality. The in situ-gelling hydrogels could be introduced through a minimally invasive procedure and adapt to the intricate anatomy of the uterus. The UCMSCs-laden injectable hydrogel promoted endometrial regeneration and fertility restoration in a rat endometrial damage model, efficaciously augmenting macrophage recruitment and promoting their polarization to the M2 phenotype. The administration of UCMSCs-laden injectable hydrogel presents a promising therapeutic strategy for patients with severe intrauterine adhesion.

Colloidal crystals array enabled bionic biliary stent for efficient domestic biofluid management

In vivo surgical interventions require effective management of biofluids, including controlling bleeding and removing excess biofluids such as bile, wound exudate, and blood. To address these issues, recent advances have emerged, such as self-sealing needles, drug-eluting stents, and shear-thinning hydrogels. However, complications associated with intestinal mucosal injury and secondary damage still persist. Therefore, a multifunctional stent is urgently required that can effectively remove excessive biofluid. Surface wettability of biliary stents is crucial in biofluid management, and conventional coatings can cause adhesion to wound tissue. To overcome this issue, we developed an interpenetrating Janus wettability stent coating, enabling unidirectional draining of excessive biofluid from its hydrophobic side to hydrophilic side, thereby preventing biofluid from wetting the wound. Furthermore, we demonstrate a directional biofluid movement using a self-pumping dressing in an infected tissue model, providing a new approach for in situ biofluid collection and disease diagnosis by detecting metal ion changes. Overall, our integrated system presents an opportunity to design wound dressings with effective biofluid management and metal ion detection capabilities.

Injectable collagen hydrogel combines human umbilical cord mesenchymal stem cells to promote endometrial regeneration in rats with thin endometrium

The regeneration of thin endometrium still remains as a great challenge in the field of reproductive medicine. Stem cells-based therapy has been considered as a promising strategy for the restoration of thin endometrium. However, the low transplantation and retention rate of stem cells and loss of stemness due to in vitro expansion limits the therapeutic efficacy. In our study, we combined collagen hydrogel and human umbilical cord mesenchymal stem cells (uMSCs) for improving the regeneration of thin endometrium, by using the potent pluripotency and low immunogenicity of uMSCs and collagen hydrogel that promotes the anchorage and proliferation of stem cells. Results showed that collagen hydrogel has favorable biocompatibility and the capacity to enhance the cell viability and expression of stemness-associated genes (including organic cation/carnitine transporter4 (Oct-4), Nanog homeobox (Nanog) and SRY-box transcription factor 2 (SOX2)) of uMSCs. The combination of collagen hydrogel and uMSCs prolonged the retention time of the constructs in the uterine cavity and improved endometrial thickness compared with uMSCs alone, leading to increase the fertility of the rats with thin endometrium. These highlighted therapeutic prospects of collagen hydrogel combined with uMSCs for the minimally invasive therapy of thin endometrium in the clinic.

Melatonin-pretreated human umbilical cord mesenchymal stem cells improved endometrium regeneration and fertility recovery through macrophage immunomodulation in rats with intrauterine adhesions†

Intrauterine adhesions (IUA) are a common gynecological problem. Stem cell therapy has been widely used in the treatment of IUA. However, due to the complex and harsh microenvironment of the uterine cavity, the effectiveness of such therapy is greatly inhibited. This study aimed to investigate whether melatonin pretreatment enhances the efficacy of human umbilical cord mesenchymal stem cells (HucMSCs) in IUA treatment in rats. First, we explored the effect of melatonin on the biological activity of HucMSCs in vitro through a macrophage co-culture system, Cell Counting Kit 8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU), flow cytometry, immunofluorescence staining, and qRT-PCR. Subsequently, we established the IUA rat model and tracked the distribution of HucMSCs in this model. In addition, we observed the number of M1 and M2 macrophages through immunofluorescence staining and detected the levels of inflammatory cytokines. Four weeks after cell transplantation, HE, Masson, and immunohistochemical staining were performed. In vitro experiments showed that melatonin pretreatment of HucMSCs promoted proliferation, reduced apoptosis, up-regulated the stemness gene, and regulated macrophage polarization. In vivo, melatonin pretreatment caused more HucMSCs to remain in the uterine cavity. Melatonin-pretreated HucMSCs recruited more macrophages, regulated macrophage polarization, and reduced inflammation. Melatonin-pretreated HucMSCs relieved fibrosis, increased endometrium thickness, and up-regulated CD34, vimentin, proliferating cell nuclear antigen (PCNA), and alpha small muscle antigen (α-SMA) expression. Fertility tests showed that melatonin-pretreated HucMSCs increased the number of embryos. In summary, pretreatment with melatonin was beneficial for HucMSC treatment because it enhanced the cell's ability to recruit macrophages and regulate macrophage polarization, which led to the regeneration of the endometrium and improved pregnancy outcomes.

A Rapid Self-Pumping Organohydrogel Dressing with Hydrophilic Fractal Microchannels to Promote Burn Wound Healing

Burn wounds pose great challenges for conventional dressings because massive exudates oversecreted from swollen tissues and blisters seriously delay wound healing. Herein, a self-pumping organohydrogel dressing with hydrophilic fractal microchannels is reported that can rapidly drain excessive exudates with ≈30 times enhancement in efficiency compared with the pure hydrogel, and effectively promote burn wound healing. A creaming-assistant emulsion interfacial polymerization approach is proposed to create the hydrophilic fractal hydrogel microchannels in the self-pumping organohydrogel through a dynamic floating-colliding-coalescing process of organogel precursor droplets. In a murine burn wound model, the rapid self-pumping organohydrogel dressings can markedly reduce dermal cavity by ≈42.5%, accelerate blood vessel regeneration by ≈6.6 times, and hair follicle regeneration by ≈13.5 times, compared with the commercial dressing (Tegaderm). This study paves an avenue for designing high-performance functional burn wound dressings.

An Acellular Scaffold Facilitates Endometrial Regeneration and Fertility Restoration via Recruiting Endogenous Mesenchymal Stem Cells

Severe intrauterine adhesions (IUAs), characterized by inadequate endometrial repair and fibrosis, can lead to infertility. Stem cell-based therapies, which deliver mesenchymal stem cells (MSCs) to the wound site, hold a considerable promise for endometrium regeneration. However, some notable hurdles, such as stemness loss, immunogenicity, low retention and survival rate, limit their clinical application. Evidence shows a strategy of mobilizing endogenous MSCs recruitment can overcome the traditional limitations of exogenous stem cell-based therapies. Here, an acellular biomaterial named stromal derived factor-1 alpha (SDF-1α)/E7-modified collagen scaffold (CES) is explored. CES based on harnessing the innate regenerative potential of the body enables near-complete endometrium regeneration and fertility restoration both in a rat endometrium acute damage model and a rat IUA model. Mechanistically, the CES implantation promotes endogenous MSCs recruitment via a macrophage-coordinated strategy; then the homing MSCs exert the function of immunomodulation and altered local microenvironments toward regeneration. To conclude, CES, which can harness endogenous MSCs and overcome the traditional limitations of cell-based therapies, can serve as a clinically feasible and cell-free strategy with high therapeutic efficiency for IUA treatment.

Recent progress of Bioinspired Hydrogel-based delivery system for endometrial repair

Endometrial injury is the main fact leading to infertility. Current treatments of endometrial injury present many problems, such as unable to achieve desired effects due to low retention and the inherent potential risk of injury. Besides, it is important to the development of bioinspired material that can mimic the natural tissue and possess native tissue topography. Hydrogel is a kind of bioinspired superhydrophilic materials with unique characteristics, such as excellent biocompatibility, biodegradability, porosity, swelling, and cross-linkage. These unique physiochemical properties of bioinspired hydrogels enable their promising application as novel delivery platform and alternative therapies for endometrial injury. In this mini review, we summarize the recent advances in bioinispred hydrogel-based delivery system for endometrial repair, including as a post-operative physical barrier and therapeutic delivery system. In addition, present status, limitations, and future perspectives are also discussed.