Hyaluronic acid encapsulated silver metal organic framework for the construction of a slow-controlled bifunctional nanostructure: Antibacterial and anti-inflammatory in intrauterine adhesion repair

Gelatin/polycaprolactone membranes promote endometrial regeneration and restore fertility

OBJECTIVE

To investigate the effectiveness of gelatin/polycaprolactone (GT/PCL) membranes for restoring endometrial structure and function and fertility in a rat model of endometrial injury.

METHODS

We randomized 125 female Sprague-Dawley (SD) rats to the sham, natural repair (NR), estrogen (E), GT/PCL, and E-GT/PCL groups. Except for the sham group, all rats underwent uterine curettage. After 1, 2, 3, and 4 weeks, 12 rats from each group were sacrificed; their uterine tissue was collected for histological, immunohistochemical, and reverse transcription quantitative-polymerase chain reaction analyses. Eight rats from each group underwent radiography of the uterine cavity. The remaining 25 females were mated with males to assess fertility 60 d postoperatively.

RESULTS

The GT/PCL and E-GT/PCL groups had higher endometrial thickness, collagen degradation, cytokeratin 19, vimentin (VIM) expression, and microvessel densities and had higher levels of estrogen receptors (ERα) but lower levels of tumor necrosis factor (TNF) than the NR and E groups. They also showed better hysterographic patency, with the shape of the uterine cavity similar to that of the sham group, and higher embryo implantation rates than the NR and E groups.

CONCLUSIONS

GT/PCL membranes promote endometrial regeneration and improve fertility in rats. They may help prevent intrauterine adhesions (IUAs) postoperatively and warrant further investigation.

Laser additive manufacturing of shape memory biopolymer bone scaffold: 3D conductive network construction and electrically driven mechanism

INTRODUCTION

The electro-actuated shape memory polymer scaffold has gained increasing attentions on the utilization of minimally invasive surgery for bone defect repair, which requires to construct an efficient conductive network to accomplish electrical-to-thermal conversion from conductive fillers to the entire matrix evenly.

OBJECTIVES

In this study, multiwall carbon nanotube (MWCNT) was convective self-assembled on the ZnO tetrapod (t-ZnO) template, where MWCNT was controlled to disperse uniformly and regulated to contact with each other effectively due to the immersion capillary force during the evaporation loss of the convective self-assembly process, leading to an interwoven layer on the t-ZnO surface.

METHODS

The prepared t-ZnO@MWCNT assembly was embedded in the poly(L-lactic acid)/thermoplastic polyurethane (PLLA/TPU) scaffold fabricated via selective laser sintering to construct a 3D conductive MWCNT network for improving the electro-actuated shape memory properties.

RESULTS

It was observed that the interconnected MWCNT formed a 3D conductive network in the matrix without significant aggregation, which boosted the electrical-to-thermal properties of the scaffold, and the scaffold containing t-ZnO@MWCNT assembly possessed better electro-actuated shape memory properties with shape fixity of 98.0% and shape recovery of 98.8%.

CONCLUSION

The scaffold exhibited improved electro-actuated shape memory properties and mechanical properties and the osteogenic inductivity was promoted with the combined effect of t-ZnO and electrical stimulation.

Zeolitic imidazolate framework-8: a versatile nanoplatform for tissue regeneration

Extensive research on zeolitic imidazolate framework (ZIF-8) and its derivatives has highlighted their unique properties in nanomedicine. ZIF-8 exhibits advantages such as pH-responsive dissolution, easy surface functionalization, and efficient drug loading, making it an ideal nanosystem for intelligent drug delivery and phototherapy. These characteristics have sparked significant interest in its potential applications in tissue regeneration, particularly in bone, skin, and nerve regeneration. This review provides a comprehensive assessment of ZIF-8's feasibility in tissue engineering, encompassing material synthesis, performance testing, and the development of multifunctional nanosystems. Furthermore, the latest advancements in the field, as well as potential limitations and future prospects, are discussed. Overall, this review emphasizes the latest developments in ZIF-8 in tissue engineering and highlights the potential of its multifunctional nanoplatforms for effective complex tissue repair.

Bio-response of copper-magnesium co-substituted mesoporous bioactive glass for bone tissue regeneration

Mesoporous bioactive glass (MBG) is widely acknowledged in bone tissue engineering due to its mesoporous structure, large surface area, and bioactivity. Recent research indicates that introduction of metallic ions has beneficial impacts on bone metabolism and angiogenesis. Thus, the features of MBG can be modified by incorporating combinations of ions, such as magnesium (Mg) and copper (Cu), which can play a considerable role in bone formation, influencing angiogenesis, osteogenesis, as well as antibacterial properties. In this study, Mg and Cu were co-doped for the first time (in a ratio of 1 : 1) in 80SiO2-5P2O5-(15 - 2x)CaO-xMgO-xCuO glass composition with x = 0, 0.5, 1, and 2 mol%, synthesized using the sol-gel and evaporation-induced self-assembly method. X-ray diffraction analysis confirmed the amorphous nature of the powders, while inductively coupled plasma-optical emission spectrometry verified the existence of dopant ions in the respective amounts. The nitrogen sorption method indicated the formation of uniform cylindrical mesopores which are open at both ends and a high surface area of the powders. TEM images show fringes, indicating an ordered mesoporous structure in all MgCu co-doped systems. In vitro bioactivity was observed in all MBG powders, confirmed by the formation of an apatite phase when placed in simulated body fluid (SBF). Flake-like microstructure characteristics of HAp crystals found on the surface of MBG powders were visualized using FESEM. Cytotoxicity tests at lower concentrations (0.1 and 1 wt/vol%) of co-doped 2MC MBG (co-doping up to 2 mol%) showed cell proliferation and viability of osteoblast-like MG-63 cells and normal human dermal fibroblast (NHDF) cells similar to the basic glass 80S. Antibacterial study of MBG pellets showed an increment in the zone of inhibition with the sequential addition of doping ions. The turbidity measurement of bacterial cultures revealed that the optimal concentration for effectively inhibiting bacterial growth was 1 wt/vol% (i.e., 10 mg mL-1) concentration of MBG extracts. The result suggested that the incorporation of Mg and Cu ions in MBG in lower concentrations of up to 2 mol% can be useful in bone regeneration owing to bioactivity, cell proliferation, and antibacterial characteristics.

Metal-organic framework-based advanced therapeutic tools for antimicrobial applications

The escalating concern over conventional antibiotic resistance has emphasized the urgency in developing innovative antimicrobial agents. In recent times, metal-organic frameworks (MOFs) have garnered significant attention within the realm of antimicrobial research due to their multifaceted antimicrobial attributes, including the sustained release of intrinsic or exogenous antimicrobial components, chemodynamically catalyzed generation of reactive oxygen species (ROS), and formation of photogenerated ROS. This comprehensive review provides a thorough overview of the synthetic approaches employed in the production of MOF-based materials, elucidating their underlying antimicrobial mechanisms in depth. The focal point lies in elucidating the research advancements across various antimicrobial modalities, encompassing intrinsic component release system, extraneous component release system, auto-catalytical system, and energy conversion system. Additionally, the progress of MOF-based antimicrobial materials in addressing wound infections, osteomyelitis, and periodontitis is meticulously elucidated, culminating in a summary of the challenges and potential opportunities inherent within the realm of antimicrobial applications for MOF-based materials. STATEMENT OF SIGNIFICANCE: Growing concerns about conventional antibiotic resistance emphasized the need for alternative antimicrobial solutions. Metal-organic frameworks (MOFs) have gained significant attention in antimicrobial research due to their diverse attributes like sustained antimicrobial components release, catalytic generation of reactive oxygen species (ROS), and photogenerated ROS. This review covers MOF synthesis and their antimicrobial mechanisms. It explores advancements in intrinsic and extraneous component release, auto-catalysis, and energy conversion systems. The paper also discusses MOF-based materials' progress in addressing wound infections, osteomyelitis, and periodontitis, along with existing challenges and opportunities. Given the lack of related reviews, our findings hold promise for future MOF applications in antibacterial research, making it relevant to your journal's readership.

pH-Responsive nanoplatform synergistic gas/photothermal therapy to eliminate biofilms in poly(L-lactic acid) scaffolds

To date, implant-associated infection is still a significant clinical challenge, which cannot be effectively eliminated by single therapies due to the formation of microbial biofilms. Herein, a pH-responsive nanoplatform was constructed via the in situ growth of zinc sulfide (ZnS) nanoparticles on the surface of Ti3C2 MXene nanosheets, which was subsequently introduced in poly(L-lactic acid) (PLLA) to prepare a composite bone scaffold via selective laser sintering technology. In the acidic biofilm microenvironment, the degradation of ZnS released hydrogen sulfide (H2S) gas to eliminate the biofilm extracellular DNA (eDNA), thus destroying the compactness of the biofilm. Then, the bacterial biofilm became sensitive to hyperthermia, which could be further destroyed under near-infrared light irradiation due to the excellent photothermal property of MXene, finally achieving gas/photothermal synergistic antibiofilm and efficient sterilization. The results showed that the synergistic gas/photothermal therapy for the composite scaffold not only evidently inhibited the formation of biofilms, but also effectively eradicated the eDNA of the already-formed biofilms and killed 90.4% of E. coli and 84.2% of S. aureus under near infrared light irradiation compared with single gas or photothermal therapy. In addition, the composite scaffold promoted the proliferation and osteogenic differentiation of mouse bone marrow mesenchymal stem cells. Thus, the designed scaffold with excellent biofilm elimination and osteogenesis ability has great potential as an alternative treatment for implant-associated bone infections.

A Cu-Based Metal-Organic Framework Cu-Cip with Cuproptosis for Cancer Therapy and Inhibition of Cancer Cell Migration

Microflora within cancer cells plays a pivotal role in promoting metastasis of cancer. However, contemporary anticancer research often overlooks the potential benefits of combining anticancer and antibacterial agents. Consequently, a metal-organic framework Cu-Cip with cuproptosis and antibacterial properties was synthesized for cancer therapy. To enhance the anticancer effect of the material, Mn2+ was loaded into Cu-Cip, yielding Mn@Cu-Cip. The fabricated material was characterized using single-crystal X-ray diffraction, PXRD, and FT-IR. By interacting with overexpressed H2O2 to produce ROS and accumulating Cu ions in cancer cells, MOFs exhibited excellent anticancer performance. Moreover, the material displayed the function of damaging Staphylococcus aureus and Escherichia coli, revealing the admirable antibacterial properties of the material. In addition, the antibacterial ability could inhibit tumor cell migration. The Cu-based MOF revealed promising applications in the field of tumor treatment.

Cyclical endometrial repair and regeneration: Molecular mechanisms, diseases, and therapeutic interventions

The endometrium is a unique human tissue with an extraordinary ability to undergo a hormone-regulated cycle encompassing shedding, bleeding, scarless repair, and regeneration throughout the female reproductive cycle. The cyclical repair and regeneration of the endometrium manifest as changes in endometrial epithelialization, glandular regeneration, and vascularization. The mechanisms encompass inflammation, coagulation, and fibrinolytic system balance. However, specific conditions such as endometriosis or TCRA treatment can disrupt the process of cyclical endometrial repair and regeneration. There is uncertainty about traditional clinical treatments' efficacy and side effects, and finding new therapeutic interventions is essential. Researchers have made substantial progress in the perspective of regenerative medicine toward maintaining cyclical endometrial repair and regeneration in recent years. Such progress encompasses the integration of biomaterials, tissue-engineered scaffolds, stem cell therapies, and 3D printing. This review analyzes the mechanisms, diseases, and interventions associated with cyclical endometrial repair and regeneration. The review discusses the advantages and disadvantages of the regenerative interventions currently employed in clinical practice. Additionally, it highlights the significant advantages of regenerative medicine in this domain. Finally, we review stem cells and biologics among the available interventions in regenerative medicine, providing insights into future therapeutic strategies.

A CuS@g-C3N4 heterojunction endows scaffold with synergetic antibacterial effect

Graphitic carbon nitride (g-C3N4) had aroused tremendous attention in photodynamic antibacterial therapy due to its excellent energy band structure and appealing optical performance. Nevertheless, the superfast electron-hole recombination and dense biofilm formation abated its photodynamic antibacterial effect. To this end, a nanoheterojunction was synthesized via in-situ growing copper sulfide (CuS) on g-C3N4 (CuS@g-C3N4). On the one hand, CuS could form Fermi level difference with g-C3N4 to accelerate carrier transfer and thus facilitate electron-hole separation. On the other hand, CuS could respond near-infrared light to generate localized thermal to disrupt biofilm. Then the CuS@g-C3N4 nanoparticle was introduced into the poly-l-lactide (PLLA) scaffold. The photoelectrochemistry results demonstrated that the electron-hole separation efficiency was apparently enhanced and thereby brought an approximate sevenfold increase in reactive oxygen species (ROS) production. The thermal imaging indicated that the scaffold possesses a superior photothermal effect, which effectively eradicated the biofilm by disrupting its extracellular DNA and thereby facilitated to the entry of ROS. The entered ROS could effectively kill the bacteria by causing protein, K+, and nucleic acid leakage and glutathione consumption. As a consequence, the scaffold displayed an antibacterial rate of 97.2% and 98.5% against E. coli and S. aureus, respectively.

Fe-doped mesoporous silica catalyzes ascorbic acid oxidation for tumor-specific therapy in scaffold

Ascorbic acid (AA) is a promising antitumor agent, yet its autooxidation is too slow which constrains the further application. Fortunately, the autoxidation process can be accelerated by transition metal catalysts, especially Fe³⁺ ions. In this study, AA was loaded to Fe-doped mesoporous silica (designated as AA@Fe-SiO₂), which was introduced into poly-L-lactic acid (PLLA) and then prepared into a scaffold. Mechanistically, AA@Fe-SiO₂ degraded in acidic tumor microenvironment because excessive H⁺ substituted Fe atoms in the iron silicate framework, releasing Fe³⁺ and AA. The Fe³⁺ boosted the pro-oxidation reaction of AA, generating numerous hydrogen peroxide (H₂O₂) and Fe²⁺. Then, Fe²⁺ reacted with H₂O₂ to initiate Fenton reactions favoring hydroxyl radical generation, triggering oxidative damage on tumor cells to implement tumor-specific therapy. Results showed that the release amount of AA in acidic solution was about 3 times higher than that in neutral solution, which was attributed to the pH-dependency of the degradation of AA@Fe-SiO₂ in scaffold. Furthermore, the scaffold generated numerous ascorbate radical intermediate and increased the H₂O₂ concentration by 120.2%, demonstrating that Fe³⁺ remarkably accelerated the oxidation rate of AA. Cell experimental results showed that the scaffold caused massive apoptosis of tumor cells, while no obvious cytotoxicity to normal cells, confirming the antitumor specificity of scaffold. This work paves a promising way to construct a biodegradable and catalytic scaffold, featuring effective tumor-specific therapy.