Establishment of a Model for Human Hypertrophic Scar Using Tissue Engineering Method.

BACKGROUND: Treatment of human hypertrophic scar (HS) is a challenge for plastic surgeons, whereas the clinical and experimental research has been limited due to the lack of an ideal model of human HS tissue. OBJECTIVE: To establish a model of human HS using tissue engineering method, to improve the research for HS in the clinic and laboratory. METHODS: Hypertrophic scar fibroblasts (HSFBs) were transferred to polylactic acid (PLA)/polyglycolic acid (PGA) scaffolds. Biocompatibility of HSFBs-PLA/PGA composites was evaluated using scanning electron microscopy. Composites of HSFBs-PLA/PGA were implanted in subcutaneous pockets in athymic mice after 4 weeks in vitro culture. A re-entry operation was performed to obtain the HS-like tissues after 12 weeks of in vivo culture. The histological stain, the expression of type I collagen, the proliferation ability, and vitality of HSFBs were compared between human HS tissue and HS-like tissue. RESULTS: The structure of PLA/PGA scaffolds facilitates HSFBs adhesion and proliferation. The HSFBs-PLA/PGA composites were in vivo cultured for 12 weeks, and then HS-like tissues were harvested from nude athymic mice. There was no statistical significance in the expression of type I collagen, cell cycle, and cell proliferation between human HS tissue and HS-like tissue. CONCLUSION: The authors successfully established a model of human HS using the tissue engineering method, which could provide HS-like tissue for research. And it also could provide enough HS-like tissues to help reduce experimental variability within groups. This model can be used to investigate in prevention and treatment of HS and further explore the mechanisms of HS.

Electrospun Hyaluronan Nanofiber Membrane Immobilizing Aromatic Doxorubicin as Therapeutic and Regenerative Biomaterial.

Lesioned tissue requires synchronous control of disease and regeneration progression after surgery. It is necessary to develop therapeutic and regenerative scaffolds. Here, hyaluronic acid (HA) was esterified with benzyl groups to prepare hyaluronic acid derivative (HA-Bn) nanofibers via electrospinning. Electrospun membranes with average fiber diameters of 407.64 ± 124.8 nm (H400), 642.3 ± 228.76 nm (H600), and 841.09 ± 236.86 nm (H800) were obtained by adjusting the spinning parameters. These fibrous membranes had good biocompatibility, among which the H400 group could promote the proliferation and spread of L929 cells. Using the postoperative treatment of malignant skin melanoma as an example, the anticancer drug doxorubicin (DOX) was encapsulated in nanofibers via hybrid electrospinning. The UV spectroscopy of DOX-loaded nanofibers (HA-DOX) revealed that DOX was successfully encapsulated, and there was a π-π interaction between aromatic DOX and HA-Bn. The drug release profile confirmed the sustained release of about 90%, achieved within 7 days. In vitro cell experiments proved that the HA-DOX nanofiber had a considerable inhibitory effect on B16F10 cells. Therefore, the HA-Bn electrospun membrane could facilitate the potential regeneration of injured skin tissues and be incorporated with drugs to achieve therapeutic effects, offering a powerful approach to developing therapeutic and regenerative biomaterial.

Lateral approach is a more aesthetical option for radical resection of BSCC: assessment of its surgical, oncological, functional, and aesthetic outcomes.

BACKGROUND: The purpose of this study was to introduce a modified lateral approach for combined radical resection of buccal squamous cell carcinoma (BSCC) and evaluate its surgical, oncological, functional, and aesthetic outcomes in comparison with the conventional lower-lip splitting approach. METHODS: This single-center study retrospectively reviewed 80 patients with BSCC, of which 37 underwent the lateral approach and 43 underwent the conventional approach. Surgical, functional, oncological, and aesthetic evaluations, as well as follow-ups, were recorded and compared. RESULTS: Compared to the conventional approach group, the lateral approach group had a longer surgical time (P = 0.000), but there was no significant difference in other surgical and oncological parameters. Moreover, the scar in the head and neck had a significantly discreet appearance in the lateral approach group, whose satisfaction was better than those in the conventional approach group (P = 0.000). Other oral function parameters, postoperative mouth-opening, and 3-year survival rate were not significantly different between the two groups. CONCLUSION: The lateral approach could provide superior aesthetic results while maintaining equal surgical, functional, and oncological outcomes compared to the conventional approach for radical resection of BSCC.

Recent Advances on Fabrication of Polymeric Composites Based on Multicomponent Reactions for Bioimaging and Environmental Pollutant Removal.

As the core of polymer chemistry, manufacture of functional polymers is one of research hotspots over the past several decades. Various polymers are developed for diverse applications due to their tunable structures and unique properties. However, traditional step-by-step preparation strategies inevitably involve some problems, such as separation, purification, and time-consuming. The multicomponent reactions (MCRs) are emerging as environmentally benign synthetic strategies to construct multifunctional polymers or composites with pendant groups and designed structures because of their features, such as efficient, fast, green, and atom economy. This mini review summarizes the latest advances about fabrication of multifunctional fluorescent polymers or adsorptive polymeric composites through different MCRs, including Kabachnik-Fields reaction, Biginelli reaction, mercaptoacetic acid locking imine reaction, Debus-Radziszewski reaction, and Mannich reaction. The potential applications of these polymeric composites in biomedical and environmental remediation are also highlighted. It is expected that this mini-review will promote the development preparation and applications of functional polymers through MCRs.

Changes in Condylar Position After Mandibular Reconstruction With Condylar Head Preservation by Computed Tomography.

PURPOSE: Condylar position can change after mandibular reconstruction using the free fibula flap. The present study evaluated changes in condylar position using computed tomography (CT) after mandibular reconstruction with condylar head preservation. MATERIALS AND METHODS: This retrospective study consisted of 16 patients. CT data of 32 temporomandibular joints (TMJs) were recorded before surgery (T0), 7 to 10 days after surgery (T1), and 16.8 ± 7.4 months after surgery (T2). The anteroposterior condylar position was evaluated using the method of Pullinger and Hollender (Oral Surg Oral Med Oral Pathol 62:719, 1986). Repeated-measures analysis of variance (P = .05) was performed. RESULTS: Data of 16 patients were obtained for statistical analysis. Condylar position changed over time after mandibular reconstruction. The ipsilateral condyles moved anteroinferiorly after surgery (T0 to T1) and tended to move anterosuperiorly during follow-up (T1 to T2). No major changes were noted in the contralateral condyles. CONCLUSION: Condylar positions showed obvious changes over time after mandibular reconstruction with condylar preservation. Nevertheless, additional studies are warranted to further evaluate the relation between condylar position and TMJ function.

[The in vivo thrombosis evaluation for the biodegradable polymer stent].

New biodegradable intravascular stent can reduce risk of foreign bodies retained, thus, it is widely concerned and some of the products have been introduced into the clinic. However, the characteristic of biodegradable may lead to more safety concerns associated with thrombosis. To ensure the safety, the thrombus formation experiment in vivo needs to be carefully designed and evaluated based on GB/T 16886.4 standard, but current standard do not provide explicit testing and evaluating methods. Establishing animal model with experimental pigs, the study compares biodegradable coronary stents and metal stents by simulating clinical implantation in vivo on the thrombus formation in the implanting process, and after the short-term and long-term implantation. The evaluation methods include gross observation, digital subtraction angiography intraoperative analysis, optical coherence tomography analysis, scanning electron microscopy and so on. The results show that combining these methods could comprehensively evaluate the whole process of the thrombus formation from the beginning of implantation to the end of preclinical animal experiments, so that, it may better predict the clinical thrombosis risk, and the selection of the control was very important. The study tries to use the comparison examples of thrombosis on the new medical instrument to provide the clue for thrombosis evaluation in vivo on similar instruments and show the methodology on the preclinical evaluation.

Surgical Reconstruction of Maxillary and Mandibular Defects Using a Printed Titanium Mesh.

PURPOSE: To reconstruct maxillary and mandibular defects with printed titanium mesh using computer-assisted surgery (CAS) for the achievement of structural, esthetic, and functional goals. PATIENTS AND METHODS: The authors designed and implemented this prospective study of patients with maxillary or mandibular defects who underwent reconstruction with printed titanium mesh using CAS. After surgery, the preoperative design and postoperative outcome were evaluated using Geomagic Studio software. RESULTS: The sample was comprised of 2 patients with maxillary defects and 2 with mandibular defects. A satisfactory contour was achieved in all patients. The rate of concordance between the preoperative design and the postoperative outcome was higher than 81 and 94% within 3 mm for the mandibular and maxillary reconstructions, respectively. CONCLUSION: The results of this study suggest that complicated maxillary and mandibular defects can be satisfactorily reconstructed with customized printed titanium meshes using CAS.

Hierarchical Scaffold with Directional Microchannels Promotes Cell Ingrowth for Bone Regeneration.

Bone regenerative scaffolds with a bionic natural bone hierarchical porous structure provide a suitable microenvironment for cell migration and proliferation. Here, a bionic scaffold (DP-PLGA/HAp) with directional microchannels is prepared by combining 3D printing and directional freezing technology. The 3D printed framework provides structural support for new bone tissue growth, while the directional pore embedded in the scaffolds provides an express lane for cell migration and nutrition transport, facilitating cell growth and differentiation. The hierarchical porous scaffolds achieve rapid infiltration and adhesion of bone marrow mesenchymal stem cells (BMSCs) and improve the expression of osteogenesis-related genes. The rabbit cranial defect experiment presents significant new bone formation, demonstrating that DP-PLGA/HAp offers an effective means to guide cranial bone regeneration. The combination of 3D printing and directional freezing technology might be a promising strategy for developing bone regenerative biomaterials.

Parotideomasseteric fascia flap is an effective management for prevention of postoperative salivary collection arising from radical surgery of oral cancer.

Salivary collection (SC) following surgery for oral cancer represents an underreported and unrecognized complication. Our study aimed to evaluate the efficacy of parotideomasseteric fascia flap (PFF) in preventing postoperative SC, comparing its effectiveness with other conventional methods. Between November 2019 and January 2023, 221 patients diagnosed with oral squamous cell carcinoma (OSCC) undergoing wide tumor ablation and neck dissection at Xiangya Hospital were included in the study. Patients were randomly allocated into four groups based on different intraoperative techniques to assess the preventive efficacy of PFF against SC. The incidence of SC in the PFF group was only 5.9%, which was significantly lower than the other three groups (p < 0.05). Among the 221 patients, the highest SC incidence occurred in buccal cancer cases (19.6%). However, in the PFF group, the incidence was not significantly different (9.5%; p > 0.05). Univariate analysis revealed a higher SC incidence associated with advanced clinical T stage (p = 0.02), N(+) stage (p = 0.01), low average serum albumin (SA) level (p = 0.00), and a large parotid wound (p = 0.00). In multivariate analysis, only average SA (p = 0.01; odds ratio [OR] 4.104; 95% CI 0.921-11.746) emerged as the most prevalent factor predisposing to SC. The utilization of PFF demonstrated a notable reduction in the incidence of postoperative SC, establishing it as a safe, effective, and convenient method for patients undergoing radical ablation for OSCC.

Aggregation behavior of polystyrene nanoplastics: Role of surface functional groups and protein and electrolyte variation.

Aggregation kinetics of plastics are affected by the surface functional groups and exposure orders (electrolyte and protein) with kinds of mechanisms in aquatic environment. This study investigates the aggregation of polystyrene nanoplastics (PSNPs) with varying surface functional groups in the presence of common electrolytes (NaCl, CaCl2, Na2SO4) and bovine serum albumin (BSA). It also examines the impact of different exposure orders, namely BSA + NaCl (adding them together), BSA → NaCl (adding BSA firstly and then NaCl), and NaCl → BSA (adding NaCl firstly and then BSA), on PSNPs aggregation. The presence of BSA decreased the critical coagulation concentration in NaCl (CCCNa+) of the non-modified PS-Bare from 222.17 to 142.81 mM (35.72%), but increased that of the carboxyl-modified PS-COOH from 157.34 to 160.03 mM (1.71%). This might be ascribed to the thicker absorbed layer of BSA onto the PS-Bare surface, known from Ohshima's soft particle theory. Their aggregation in CaCl2 was both increased because of Ca2+ bridging. Different from the monotonous effects of BSA on PS-Bare and PS-COOH, BSA initially facilitated PS-NH2 aggregation via patch-charge attraction, then inhibited it at higher salt levels through steric repulsion. Furthermore, exposure orders had no significant effect on PS-Bare and PS-COOH, but had a NaCl concentration-dependent impact on PS-NH2. At the low NaCl concentrations (10 and 100 mM), no obvious influence could be observed. While, at 300 mM NaCl, the high concentrations of BSA could not totally stabilize the salt-induced aggregates in NaCl → BSA, but could achieve it in the other two orders. These might be attributed to the electrical double layer compression by NaCl, "patch-charge" force and steric hindrance by BSA. These experimental findings shed light on the potential fate and transport of nanoparticles in aquatic environments.

Injectable Microgels with Hybrid Exosomes of Chondrocyte-Targeted FGF18 Gene-Editing and Self-Renewable Lubrication for Osteoarthritis Therapy.

Abnormal silencing of fibroblast growth factor (FGF) signaling significantly contributes to joint dysplasia and osteoarthritis (OA); However, the clinical translation of FGF18-based protein drugs is hindered by their short half-life, low delivery efficiency and the need for repeated articular injections. This study proposes a CRISPR/Cas9-based approach to effectively activate the FGF18 gene of OA chondrocytes at the genome level in vivo, using chondrocyte-affinity peptide (CAP) incorporated hybrid exosomes (CAP/FGF18-hyEXO) loaded with an FGF18-targeted gene-editing tool. Furthermore, CAP/FGF18-hyEXO are encapsulated in methacrylic anhydride-modified hyaluronic (HAMA) hydrogel microspheres via microfluidics and photopolymerization to create an injectable microgel system (CAP/FGF18-hyEXO@HMs) with self-renewable hydration layers to provide persistent lubrication in response to frictional wear. Together, the injectable CAP/FGF18-hyEXO@HMs, combined with in vivo FGF18 gene editing and continuous lubrication, have demonstrated their capacity to synergistically promote cartilage regeneration, decrease inflammation, and prevent ECM degradation both in vitro and in vivo, holding great potential for clinical translation.

Engineered Microchannel Scaffolds with Instructive Niches Reinforce Endogenous Bone Regeneration by Regulating CSF-1/CSF-1R Pathway.

Structural and physiological cues provide guidance for the directional migration and spatial organization of endogenous cells. Here, a microchannel scaffold with instructive niches is developed using a circumferential freeze-casting technique with an alkaline salting-out strategy. Thereinto, polydopamine-coated nano-hydroxyapatite is employed as a functional inorganic linker to participate in the entanglement and crystallization of chitosan molecules. This scaffold orchestrates the advantage of an oriented porous structure for rapid cell infiltration and satisfactory immunomodulatory capacity to promote stem cell recruitment, retention, and subsequent osteogenic differentiation. Transcriptomic analysis as well as its in vitro and in vivo verification demonstrates that essential colony-stimulating factor-1 (CSF-1) factor is induced by this scaffold, and effectively bound to the target colony-stimulating factor-1 receptor (CSF-1R) on the macrophage surface to activate the M2 phenotype, achieving substantial endogenous bone regeneration. This strategy provides a simple and efficient approach for engineering inducible bone regenerative biomaterials.

Molecular co-assembled strategy tuning protein conformation for cartilage regeneration.

The assembly of oligopeptide and polypeptide molecules can reconstruct various ordered advanced structures through intermolecular interactions to achieve protein-like biofunction. Here, we develop a "molecular velcro"-inspired peptide and gelatin co-assembly strategy, in which amphiphilic supramolecular tripeptides are attached to the molecular chain of gelatin methacryloyl via intra-/intermolecular interactions. We perform molecular docking and dynamics simulations to demonstrate the feasibility of this strategy and reveal the advanced structural transition of the co-assembled hydrogel, which brings more ordered ß-sheet content and 10-fold or more compressive strength improvement. We conduct transcriptome analysis to reveal the role of co-assembled hydrogel in promoting cell proliferation and chondrogenic differentiation. Subcutaneous implantation evaluation confirms considerably reduced inflammatory responses and immunogenicity in comparison with type I collagen. We demonstrate that bone mesenchymal stem cells-laden co-assembled hydrogel can be stably fixed in rabbit knee joint defects by photocuring, which significantly facilitates hyaline cartilage regeneration after three months. This co-assembly strategy provides an approach for developing cartilage regenerative biomaterials.

Construction of IMMS Containing Multi-site Liposomes for Dynamic Monitoring of Blood CTC in Patients with Osimertinib-resistant Non-small-cell Lung Cancer and its Mechanism.

OBJECTIVE: This article aims to establish a liquid biopsy system for gene detection of circulating tumor cells (CTC) in lung cancer, systematically analyze the significance of osimertinib resistance, and formulate an individualized diagnosis and treatment plan. METHODS: Liposome-contained magnetic microspheres coated with Fe3O4 nanoparticles were synthesized by microemulsion, and the surface was modified with EGFR antibody to form EGFR/EpCAM multi-site liposome-contained immunomagnetic microspheres (IMMSs). The CTCs were isolated and identified from peripheral blood samples and the cell lines of lung cancer patients collected by the multi-site liposome-contained IMMSs. To investigate the effects of the order of use of IMMSs sequence at different sites on the sorting and trapping efficiency of non-small-cell lung cancer (NSCLC) cells . The preliminary verification of drug-resistant gene function and dynamic monitoring of CTCs in 20 patients with EGFR-positive NSCLC were screened and statistically analyzed before and after osimertinib treatment. Sensitivity analysis and drug resistance evaluation of oxitidine were detected in vitro. RESULTS: Results showed the prepared multi-site liposome-contained IMMSs had high stability and specificity. The number of CTCs in blood samples of the patients with NSCLC was detected, revealing high sorting efficiency, and positive sorting rate reaching more than 90%. We investigated the effect of osimertinib on the HER-2 expression on the EGFR-mutated NSCLC cells and found that osimertinib increased the expression of HER-2 on the cell surface of NSCLC cell lines., And further explored the therapeutic potential of osimertinib combined with T-DM1 at different dosing times. CONCLUSION: Our results demonstrate that the prepared multi-site liposome-contained IMMSs can efficiently isolate CTCs from the peripheral blood in lung cancer. Combined with the experimental data about osimertinib can be effectively identified, the resistant genes of NSCLC including EGFR, which will provide a new scientific basis for guiding clinical medication and formulating individualized treatment plans.

Design and validation of performance-oriented injectable chitosan thermosensitive hydrogels for endoscopic submucosal dissection.

Endoscopic submucosal dissection (ESD) is a challenging procedure. The use of biomaterials to improve the operator's convenience (operating affinity) has received little attention. We prepared two thermosensitive hydrogels, lactobionic acid-modified chitosan/chitosan/ß-glycerophosphate thermosensitive hydrogel (hydrogel 1) and its lyophilized powders (hydrogel 2), characterized their physicochemical properties and evaluated their performance in ESD experiments on large animals, by comparing with the commonly used normal saline (NS) and glycerin fructose (GF). These hydrogels showed good low-temperature fluidity; their viscosities at 4 °C were 92.2 mPa.s and 26.9 mPa.s, respectively. The hydrogels provided significantly better viscoelastic properties than NS and GF. The relaxation moduli of hydrogels were higher than those of NS and GF when the strains were 1 %, 5 %, and 10 %. The hydrogels can be maintained for seven days, even at pH 1, after which they degrade entirely. In pig model experiments, we performed submucosal injection and ESD procedures in the stomach and esophagus. The cushion height produced by the hydrogels was higher than those of NS and GF 30 min after injection. The ESD operation time for hydrogels was significantly shorter. Postoperative wound observation and histological analysis showed that the hydrogels promoted wound healing. The two hydrogels differed in fluidity, viscoelasticity, and other properties, which makes it possible to select the hydrogels according to the size and location of the lesion during ESD operation, and hydrogel 2 may be more suitable for use in lengthier procedures. In general, the hydrogels showed good performance, facilitated the intraoperative operation of ESD, shorten the operation time and promoted wound healing, which is of great significance for reducing the complications and reducing the threshold of ESD operation and further promoting the popularity of ESD.

Effects of environmental and anthropogenic factors on the distribution and abundance of microplastics in freshwater ecosystems.

Although microplastics are emerging marine pollutants that have recently attracted increasing attention, it is still difficult to identify their sources. This study reviewed 6487 articles to determine current research trends and found 237 effective concentration points after sorting, which were distributed in four regions and related to freshwater ecosystems. Results found that 15 environmental variables represented natural and anthropogenic environmental characteristics, of which seven environmental variables were selected for experimental modelling. Random forest models fitted sample data, thus facilitating the identification of regional microplastics distribution. The global random forest model had random forest importance scores (RFISs) for gross domestic product, population, and the proportion of agricultural land use were 15.76 %, 15.64 %, and 14.74 %, respectively; these indicate that human activities significantly affected the global distribution of microplastics. In Asia, agriculture and urban activities are the main sources of microplastics, with an RFIS of 11.58 % and 12.24 % for the proportion of agricultural and urban land use, respectively. Activities in urban areas were determined to be the main influencing factors in North America, with an RFIS of 13.92 % for the proportion of urban land use. Agricultural activities were the main influencing factors in Europe, with RFISs for the proportion of agricultural land use of 16.90 %. Our results indicate that region-specific policies are required to control microplastics in different regions, with soil composition being a latency factor that affects microplastics' distribution.

Higher toxicity induced by co-exposure of polystyrene microplastics and chloramphenicol to Microcystis aeruginosa: Experimental study and molecular dynamics simulation.

Antibiotics and microplastics (MPs) inevitably coexist in natural waters, but their combined effect on aquatic organisms is still ambiguous. This study investigated the individual and combined toxicity of chloramphenicol (CAP) and micro-polystyrene (mPS) particles to Microcystis aeruginosa by physiological biomarkers, related gene expression, and molecular dynamics simulation. The results indicated that both individual and joint treatments threatened algal growth, while combined toxicity was higher than the former. Photosynthetic pigments and gene expression were inhibited by single CAP and mPS exposure, but CAP dominated and aggravated photosynthetic toxicity in combined exposure. Additionally, mPS damaged cell membranes and induced oxidative stress, which might further facilitate the entry of CAP into cells during co-exposure. The synergistic effect of CAP and mPS might be explained by the common photosynthetic toxicity target of CAP and mPS as well as oxidative stress. Furthermore, the molecular dynamics simulation revealed that CAP altered conformations of photosynthetic assembly protein YCF48 and SOD enzyme, and competed for functional sites of SOD, thus disturbing photosynthesis and antioxidant systems. These findings provide useful insights into the combined toxicity mechanism of antibiotics and MPs as well as highlight the importance of co-pollutant toxicity in the aquatic environment.

Polyvinyl-alcohol, chitosan and graphene-oxide composed conductive hydrogel for electrically controlled fluorescein sodium transdermal release.

Accurate and controlled release of drug molecules is crucial for transdermal drug delivery. Electricity, as an adjustable parameter, offers the potential for precise and controllable drug delivery. However, challenges exist in selecting the appropriate drug carrier, electrical parameters, and release model to achieve controlled electronic drug release. To overcome these challenges, this study designed a functional hydrogel using polyvinyl alcohol, chitosan, and graphene oxide as components that can conduct electricity, and constructed a drug transdermal release model using fluorescein sodium salt with proper electrical parameters. The results demonstrated that the hydrogel system exhibited low cytotoxicity, good conductivity, and desirable drug delivery characteristics. The study also integrated the effects of drug release and tissue repair promotion under electrical stimulation. Cell growth was enhanced under low voltage direct current pulses, promoting cell migration and the release of VEGF and FGF. Furthermore, the permeability of fluorescein sodium salt in the hydrogel increased with direct current stimulation. These findings suggest that the carbohydrate polymers hydrogel could serve as a drug carrier for controlled release, and electrical stimulation offers new possibilities for functional drug delivery and transdermal therapy.

Nanocomposite hydrogel based on chitosan/laponite for sealing and repairing tracheoesophageal fistula.

Tracheoesophageal fistula (TEF) is an abnormal connection between the trachea and esophagus that severely impairs quality of life. Current treatment options have limitations, including conservative treatment, surgical repair, and esophageal stent implantation. Here, we introduced laponite (LP) nano-clay to improve chitosan-based hydrogels' rheological properties and mechanical properties and developed an endoscopically injectable nanocomposite shear-thinning hydrogel to seal and repair fistulas as an innovative material for the treatment of TEF. Excellent injectability, rheological properties, mechanical strength, self-healing, biodegradability, biocompatibility, and tissue repair characterize the new hydrogel. The introduction of LP nano-clay improves the gel kinetics problem of hydrogels to realize the sol-gel transition immediately after injection, avoiding gel flow to non-target sites. The addition of LA nano-clay can significantly improve the rheological properties and mechanical strength of hydrogels, and hydrogel with LP content of 3 % shows better comprehensive performance. The nanocomposite hydrogel also shows good cytocompatibility and can promote wound repair by promoting the migration of HEEC cells and the secretion of VEGF and FGF. These findings suggest that this nanocomposite hydrogel is a promising biomaterial for TEF treatment.

Metal-phenolic self-assembly shielded probiotics in hydrogel reinforced wound healing with antibiotic treatment.

Living probiotics secrete bioactive substances to accelerate wound healing, but the clinical application of antibiotics inhibits the survival of probiotics. Inspired by the chelation of tannic acid and ferric ions, we developed a metal-phenolic self-assembly shielded probiotic (Lactobacillus reuteri, L. reuteri@FeTA) to prevent interference from antibiotics. Here, a superimposing layer was formed on the surface of L. reuteri to adsorb and inactivate antibiotics. These shielded probiotics were loaded into an injectable hydrogel (Gel/L@FeTA) formed by carboxylated chitosan and oxidized hyaluronan. The Gel/L@FeTA aided the survival of probiotics and supported the continuous secretion of lactic acid to perform biological functions in an environment containing gentamicin. Furthermore, the Gel/L@FeTA hydrogels presented a better performance than the Gel/L in inflammatory regulation, angiogenesis, and tissue regeneration both in vitro and in vivo in the presence of antibiotics. Hence, a new method for designing probiotic-based biomaterials for clinical wound management is provided.