Revolutionizing healthcare: Harnessing nano biotechnology with zinc oxide nanoparticles to combat biofilm and bacterial infections-A short review.

A crucial pathogenic mechanism in many bacterial diseases is the ability to create biofilms. Biofilms are suspected to play a role in over 80 % of microbial illnesses in humans. In light of the critical requirement for efficient management of bacterial infections, researchers have explored alternative techniques for treating bacterial disorders. One of the most promising ways to address this issue is through the development of long-lasting coatings with antibacterial properties. In recent years, antibacterial treatments based on metallic nanoparticles (NPs) have emerged as an effective strategy in the fight over bacterial drug resistance. Zinc oxide nanoparticles (ZnO-NPs) are the basis of a new composite coating material. This article begins with a brief overview of the mechanisms that underlie bacterial resistance to antimicrobial drugs. A detailed examination of the properties of metallic nanoparticles (NPs) and their potential use as antibacterial drugs for curing drug-sensitive and resistant bacteria follows. Furthermore, we assess metal nanoparticles (NPs) as powerful agents to fight against antibiotic-resistant bacteria and the growth of biofilm, and we look into their potential toxicological effects for the development of future medicines.

Optimal ultrasonic treatment frequency and duration parameters were used to detect the pathogenic bacteria of orthopedic implant-associated infection by ultrasonic oscillation.

INTRUDUCTON: The most accurate method for detecting the pathogen of orthopedic implant-associated infections (OIAIs) is sonication fluid (SF). However, the frequency and duration of ultrasound significantly influence the number and activity of microorganisms. Currently, there is no consensus on the selection of these two parameters. Through this study, the choice of these two parameters is clarified. METHODS: We established five ultrasonic groups (40kHz/10min, 40kHz/5min, 40 kHz/1min, 20kHz/5min, and 10kHz/5min) based on previous literature. OIAIs models were then developed and applied to ultrasound group treatment. Subsequently, we evaluated the efficiency of bacteria removal by conducting SEM and crystal violet staining. The number of live bacteria in the SF was determined using plate colony count and live/dead bacteria staining. RESULTS: The results of crystal violet staining revealed that both the 40kHz/5min group and the 40kHz/10min group exhibited a significantly higher bacterial clearance rate compared to the other groups. However, there was no significant difference between the two groups. Additionally, the results of plate colony count and fluorescence staining of live and dead bacteria indicated that the number of live bacteria in the 40kHz/5min SF group was significantly higher than in the other groups. CONCLUSION: 40kHz/5min ultrasound is the most beneficial for the detection of pathogenic bacteria on the surface of orthopedic implants.

Double Network Physical Crosslinked Hydrogel for Healing Skin Wounds: New Formulation Based on Polysaccharides and Zn2.

Developing convenient, efficient, and natural wound dressings remain the foremost strategy for treating skin wounds. Thus, we innovatively combined the semi-dissolved acidified sol-gel conversion method with the internal gelation method to fabricate SA (sodium alginate)/CS (chitosan)/Zn2+ physically cross-linked double network hydrogel and named it SA/CS/Zn2+ PDH. The characterization results demonstrated that increased Zn2+ content led to hydrogels with improved physical and chemical properties, such as rheology, water retention, and swelling capacity. Moreover, the hydrogels exhibited favorable antibacterial properties and biocompatibility. Notably, the establishment of an in vitro pro-healing wound model further confirmed that the hydrogel had a superior ability to repair wounds and promote skin regeneration. In future, as a natural biomaterial with antimicrobial properties, it has the potential to promote wound healing.

Marine polysaccharide laminarin embedded ZnO nanoparticles and their based chitosan capped ZnO nanocomposites: Synthesis, characterization and in vitro and in vivo toxicity assessment.

In the current scenario where more and more products containing nanomaterials are on the technological or pharmaceutical market, it is crucial to have a thorough knowledge of their toxicity before proposing possible applications. A proper analysis of the toxicity of the nanoproducts should include both in vitro and in vivo biological approaches and should consider that the synthesis and purification methods of nanomaterials may affect such toxicity. In the current work, the green synthesis of laminarin embedded ZnO nanoparticles (Lm-ZnO NPs) and their based chitosan capped ZnO nanocomposites (Ch-Lm-ZnO NCmps) is described for the first time. Furthermore, the evaluation of their in vitro cytotoxicity, phytotoxicity, and in vivo (Zebrafish embryo) toxicity was described. First, the green synthesized Lm-ZnO NPs and Ch-Lm-ZnO NCmps were fully physicochemically characterized. Lm-ZnO NPs were greatly agglomerated and had a spindle morphology ranging from 100 to 350 nm, while Ch-Lm-ZnO NCmps had irregular rod shape with flake-like structure clusters randomly aggregated with diverse sizes ranging from 20 to 250 nm. The in vitro cytotoxicity assessment of the green synthesized Lm-ZnO NPs and Ch-Lm-ZnO NCmps was carried out in normal human dermal fibroblasts (HDF) cells and human colon cancer (HT-29) cells by MTT assay. Lm-ZnO NPs and Ch-Lm-ZnO NCmps (0.1-500 µg/mL), significantly inhibited the viability of both cell lines, revealing dose-dependent cytotoxicity. Besides, the Lm-ZnO NPs and Ch-Lm-ZnO NCmps significantly affected seed germination and roots and shoots length of mung (Vigna radiata). Moreover, the zebrafish embryo toxicity of Lm-ZnO NPs and Ch-Lm-ZnO NCmps among the various concentrations used (0.1-500 µg/mL) caused deformities, increased mortality and decreased the survival rate of zebrafish embryo dose-dependently.

Preparation of Ion2+-COS/SA Multifunctional Gel Films for Skin Wound Healing by an In Situ Spray Method.

The rapid preparation of safe and efficient wound dressings that meet the needs of the entire repair process remains a major challenge for effective therapeutic wound healing. Natural, sprayable Ion2+-COS/SA multifunctional dual-network gel films created by the in situ coordination of chitooligosaccharide (COS), metal ions and sodium alginate (SA) using casting and an in-situ spray method were synthesized. The gel films exhibited excellent physicochemical properties such as swelling, porosity and plasticity at a COS mass fraction of 3%. Furthermore, at this mass fraction, the addition of bimetallic ions led to the display of multifunctional properties, including significant antioxidant, antibacterial and cytocompatibility properties. In addition, experiments in a total skin defect model showed that this multifunctional gel film accelerates wound healing and promotes skin regeneration. These results suggest that the sprayable Ion2+-COS/SA multifunctional pro-healing gel film may be a promising candidate for the clinical treatment of allodermic wounds.

South Indian medicinal plants can combat deadly viruses along with COVID-19? - A review.

SARS-CoV-2 is a causative agent of Coronavirus disease-19 (COVID-19), which is considered as a fatal disease for public health apprehension worldwide. This pathogenic virus can present everywhere. As it is a virus it can extend easily and cause severe illness to humans. Hence, an efficient international attentiveness of plan is necessary to cure and prevent. In this review, epidemic outbreak, clinical findings, prevention recommendations of COVID-19 and suggestive medicinal value of south Indian plant sources have been discussed. Though the varieties of improved approaches have been taken in scientific and medicinal concern, we have to pay attention to the medicinal value of the plant-based sources to prevent these types of pandemic diseases. This is one of the suggestive and effective ways to control the spreading of viruses. In the future, it is required to provide medicinal plant-based clinical products (Masks, sanitizers, soap, etc.,) with better techniques by clinicians to contend the scarcity and expose towards the nature-based medicine rather than chemical drugs. This may be a benchmark for the economical clinical trials of specific plant material to treat the viral diseases in the future.

SSRP1 promotes colorectal cancer progression and is negatively regulated by miR-28-5p.

In this study, microarray data analysis, real-time quantitative PCR and immunohistochemistry were used to detect the expression levels of SSRP1 in colorectal cancer (CRC) tissue and in corresponding normal tissue. The association between structure-specific recognition protein 1 (SSRP1) expression and patient prognosis was examined by Kaplan-Meier analysis. SSRP1 was knocked down and overexpressed in CRC cell lines, and its effects on proliferation, cell cycling, migration, invasion, cellular energy metabolism, apoptosis, chemotherapeutic drug sensitivity and cell phenotype-related molecules were assessed. The growth of xenograft tumours in nude mice was also assessed. MiRNAs that potentially targeted SSRP1 were determined by bioinformatic analysis, Western blotting and luciferase reporter assays. We showed that SSRP1 mRNA levels were significantly increased in CRC tissue. We also confirmed that this upregulation was related to the terminal tumour stage in CRC patients, and high expression levels of SSRP1 predicted shorter disease-free survival and faster relapse. We also found that SSRP1 modulated proliferation, metastasis, cellular energy metabolism and the epithelial-mesenchymal transition in CRC. Furthermore, SSRP1 induced apoptosis and SSRP1 knockdown augmented the sensitivity of CRC cells to 5-fluorouracil and cisplatin. Moreover, we explored the molecular mechanisms accounting for the dysregulation of SSRP1 in CRC and identified microRNA-28-5p (miR-28-5p) as a direct upstream regulator of SSRP1. We concluded that SSRP1 promotes CRC progression and is negatively regulated by miR-28-5p.

Peroral Endoscopic Myotomy with the Stag Beetle Knife (SB Knife): Feasibility and Follow-Up.

BACKGROUND Recently, a stag beetle (SB) knife was introduced to reduce the difficulty of peroral endoscopic myotomy (POEM). The objective of this study was to evaluate the efficacy and safety of the SB knife. MATERIAL AND METHODS A total of 71 patients undergoing POEM with the SB knife for esophageal achalasia were included. We used esophagography, manometry, esophagogastroduodenoscopy (EGD), and Eckardt score to assess the utility and safety. RESULTS All cases were completed for POEM. The incidence of adverse events during the operation were 2.8%; however, all cases were treated conservatively. There was a vast improvement in clinical symptoms and endoscopic findings. The average Eckardt score was 6.9 before and 0.6 at 1 year after POEM (p<0.05). The average lower esophageal sphincter (LES) pressure before and 6 months after POEM were 44.34±14.83 mmHg and 19.14±6.74 mmHg (p<0.05), respectively. The average LES relaxation pressure before and 6 months after POEM was 12.11±5.02 mmHg and 3.22±2.29 mmHg (p<0.05), respectively. CONCLUSIONS POEM with the SB Knife is technically efficient and safe in treating achalasia and is associated with favorable short-term outcomes.

Imine Bond- and Coordinate Bond-Linked pH-Sensitive Cisplatin Complex Nanoparticles for Active Targeting to Tumor Cells.

Aldehyde hyaluronic acid-cisplatin (A-HA-CDDP) complex nanoparticles were readily prepared, and CDDP was stably loaded into the core of the NPs through imine bond and coordinate bond linkages. The results show that the NPs were prepared successfully by a chemical complexation reaction rather than by physical mixing. Compared to many CDDP and HA complex nanoparticles evaluated in other studies, A-HA-CDDP NPs with imine and coordinate bonds between the A-HA and CDDP displayed better sustained release behavior and pH sensitivity. Therefore, the acidic tumor environment could accelerate the release of CDDP from the NPs. MTT and AO/EB staining assays showed that A-HA-CDDP NPs had comparable cell inhibition with CDDP in HeLa cells as well as little toxicity to NIH3T3 cells. This result indicates that the chemical reaction between A-HA and CDDP had little effect on the antitumor activity of CDDP and that the NPs actively targeted CD44-rich tumor cells. Both a hemolysis test and a protein adsorption assay demonstrated that A-HA-CDDP NPs had good biocompatibility and blood circulation in vivo. Therefore, the NPs have the potential to be used for targeted CDDP delivery in vivo. A subsequent publication will describe the circulation, targeting and tumor inhibition experiments of these NPs in vivo.

Multiresponsive and biocompatible self-healing hydrogel: its facile synthesis in water, characterization and properties.

Multiresponsive and biocompatible self-healing ε-PL/A-Pul/BPEI hydrogels were prepared in aqueous solution by Schiff base reaction with aldehyded pullulan (A-Pul), ε-poly-l-lysine (ε-PL) and branched polyethyleneimine (BPEI) as materials. The imine bonds were rapidly cross-linked into a hydrogel network within 80 s. Scanning electron microscopy images showed that the hydrogels exhibited a cross-linked structure with the average pore size from 58 to 82 µm. Rheology tests indicated that the hydrogels maintained good mechanical properties. Water contact angles and swelling studies suggested that the hydrogels could swell in water, with a max swell ratio of 1559%, and pH and temperature had an influence on the equilibrium swelling ratio. The hydrogels could be injected either before or after gelation, and they displayed a self-healing process in ddH2O at room temperature based on the dynamic uncoupling and recoupling of the imine bonds. The MTT assays implied that the hydrogels were non-cytotoxic on mice bone marrow mesenchymal stem cells. Therefore, the hydrogels showed potential application in biomedical fields, and consequently further work was performed using the self-healing hydrogels as drug carriers in in vitro/vivo antitumor studies.

Gelatin/carboxymethylcellulose composite film combined with photodynamic antibacterial: New prospect for fruit preservation.

Plastic packaging causes environmental pollution, and the development of simple and effective biodegradable active packaging remains a challenge. In this study, gelatin (G) and sodium carboxymethylcellulose (CMC) were used as film materials, with the addition of curcumin (Cur), a photosensitive substance, to investigate the changes in the physical and chemical properties of the film and its application in fruit preservation. The results demonstrated that Cur was compatible with the film. With the addition of Cur, the thickness of the film increased up to 1.3 times, while the moisture content was reduced to 12.10 %. The tensile strength (TS) and elongation at break (EAB) of the film can reach 8.84 MPa and 19.33 %, respectively. The photodynamic antibacterial experiment revealed that the film containing 0.5 % Cur exhibited the highest antibacterial rate, reaching 99.99 % against Staphylococcus aureus (S. aureus) and 95 % against Escherichia coli (E. coli). During storage, the grapes remained unspoiled for up to 9 days after being phototreated with the film and the microbial content of the skin was much lower than that of the control group. In addition, Cur provided antioxidant activity for the film, with a scavenging activity of 39.54 % against the 2,2-diphenyl-1-picrind radical (DPPH). Bananas exposed to the film-forming solution for a short period of time remained fresh for up to 6 days. During preservation, the weight of the treated bananas decreased more slowly than that of the control group. In addition, the activity of SOD on the 7th day was approximately 20 U/g higher than that of the control group, which helped to reduce oxidative stress during banana preservation. In summary, G-CMC/Cur film is an optional fruit-cling film that can be used in food packaging.

The application of ERAS in the perioperative period management of patients for lung transplantation.

Objective: To explore the application of enhanced recovery after surgery (ERAS) in the perioperative period of lung transplantation. Methods: We retrospectively collected the clinical data of 27 lung transplant patients who underwent ERAS during the perioperative period, while 12 lung transplant patients receiving routine treatment served as controls. General information was collected, including the specific implementation plan of ERAS, the incidence of complications and survival rate during the perioperative period (<30 d), postoperative hospitalization indicators, the postoperative length of stay, and numerical rating scale (NRS) scores. Results: Comparison of postoperative hospitalization indicators, the ERAS group compared with the control group, there were significant differences in postoperative ICU stay time (2.0(2.0,4.0) vs 4.5(3.0,6.0), p = 0.005), postoperative hospital stay time (18(15,26) vs 24(19.5,32.75), p = 0.016), duration of nasogastric tube (3(2,3) vs 4(2.25,4.75), p = 0.023), and first ambulation time (4(3,5) vs 5.8(4.5,7.5), p = 0.004). There was no significant difference in postoperative invasive mechanical ventilation time, time to eat after surgery, duration of urinary catheter and duration of chest tube between the ERAS group and the control group (p>0.05). The perioperative survival of the ERAS group was 81.5%, which was higher than the control group (66.7%), but there is no statistically significant difference. Comparison of post-extubation NRS scores, the ERAS group had lower NRS scores at 12 h (5.30 ± 0.14 vs 6.25 ± 0.75), 24 h (3.44 ± 0.64 vs 5.58 ± 0.9), 48 h (2.74 ± 0.66 vs 4.08 ± 0.79) and 72 h (1.11 ± 0.80 vs 2.33 ± 0.49) than the control group, the difference was statistically significant (p<0.01). Intra-group comparison, post-extubation 12 h comparison post-extubation 24 h, 48 h, 72 h, the NRS scores showed a gradual downward trend, the difference was statistically significant (p<0.01). In the comparison of perioperative complications, the ERAS group had a lower postoperative infection incidence than the control group, the difference was statistically significant (44.4% vs 83.3%, p = 0.037). The ERAS group had lower postoperative delirium incidence than the control group, the difference was statistically significant (11.1% vs 50%, p = 0.014). There was no significant difference in the incidence of acute rejection, primary graft loss (PGD), gastrointestinal (GI) complications and airway complications between two groups (p>0.05). Conclusion: The ERAS can be applied to lung transplant patients to relieve postoperative pain, shorten postoperative tube time, and shorten postoperative stay. Perioperative pulmonary rehabilitation exercises are beneficial to reducing the occurrence of postoperative pulmonary complications.

Novel Antioxidant Self-Assembled Peptides Extracted from Azumapecten farreri Meat: In Vitro- and In Silico-Assisted Identification.

Previous studies have found that the self-assembled supramolecules of Azumapecten farreri meat peptides have antioxidant effects. Therefore, this study aims to isolate and identify novel antioxidant peptides with self-assembly characteristics and analyze their structure-activity relationship through molecular docking and molecular dynamics simulation. The in vitro results show that as the purification steps increased, the antioxidant activity of peptides became stronger. Additionally, the purification step did not affect its pH-responsive self-assembly. Using LC-MS/MS, 298 peptide sequences were identified from the purified fraction PF1, and 12 safe and antioxidant-active peptides were acquired through in silico screening. The molecular docking results show that they had good binding interactions with key antioxidant-related protein ligands (KEAP1 (Kelch-like ECH-associated protein 1) and MPO (myeloperoxidase)). The peptide QPPALNDSYLYGPQ, with the lowest docking energy, was selected for a 100 ns molecular dynamics simulation. The results show that the peptide QPPALNDSYLYGPQ exhibited excellent stability when docked with KEAP1 and MPO, thus exerting antioxidant effects by regulating the KEAP1-NRF2 pathway and inhibiting MPO activity. This study further validates the antioxidant and self-assembling properties of the self-assembled supramolecules of Azumapecten farreri meat peptide and shows its potential for developing new, effective, and stable antioxidants.

Use of Metagenomic Next-Generation Sequencing to Identify Pathogens Involved in Central Nervous System Infections.

Purpose: Application of metagenomic next-generation sequencing (mNGS) in identifying nosocomial central nervous system (CNS) infections in critical care units remains understudied. Methods: We conducted a retrospective analysis of microbiological results through both mNGS and routine examination of cerebrospinal fluid (CSF) samples from patients with nosocomial CNS infections. The aim of this study was to assess the clinical diagnostic effect of nosocomial mNGS in this population. Results: The study included 26 cases of nosocomial CNS infections in total. A total of 69.2% (18/26) of the samples tested positive for mNGS, which is substantially greater than the 7.7% (2/26; p<0.05) detected through conventional techniques. Administration of antibiotics before culture is most likely the cause of the low CSF culture rate. Twenty-five pathogenic strains that were missed by standard testing. Three pathogens that were consistent with the mNGS results were positive by routine tests. Eight cases were negative by mNGS due to low pathogen CSF titres. Compared to traditional testing, mNGS demonstrated 100% sensitivity and 33.3% specificity in diagnosing CNS infections. The thirty-day mortality rate was 26.9% (7/26). Conclusion: Routine microbiologic testing frequently falls short of detecting all neuroinvasive pathogens. Our research suggests that mNGS offers an alternative means of detecting nosocomial CNS infections. By applying mNGS to CSF samples from patients with meningitis or encephalitis, we were able to improve the ability to diagnose nosocomial neurologic infections.

A new technique of percutaneous minimally invasive surgery assisted by magnetic resonance neurography.

Aims: In order to release the contracture band completely without damaging normal tissues (such as the sciatic nerve) in the surgical treatment of gluteal muscle contracture (GMC), we tried to display the relationship between normal tissue and contracture bands by magnetic resonance neurography (MRN) images, and to predesign a minimally invasive surgery based on the MRN images in advance. Methods: A total of 30 patients (60 hips) were included in this study. MRN scans of the pelvis were performed before surgery. The contracture band shape and external rotation angle (ERA) of the proximal femur were also analyzed. Then, the minimally invasive GMC releasing surgery was performed based on the images and measurements, and during the operation, incision lengths, surgery duration, intraoperative bleeding, and complications were recorded; the time of the first postoperative off-bed activity was also recorded. Furthermore, the patients' clinical functions were evaluated by means of Hip Outcome Score (HOS) and Ye et al's objective assessments, respectively. Results: The contracture bands exhibited three typical types of shape - feather-like, striped, and mixed shapes - in MR images. Guided by MRN images, we designed minimally invasive approaches directed to each hip. These approaches resulted in a shortened incision length in each hip (0.3 cm (SD 0.1)), shorter surgery duration (25.3 minutes (SD 5.8)), less intraoperative bleeding (8.0 ml (SD 3.6)), and shorter time between the end of the operation and the patient's first off-bed activity (17.2 hours (SD 2.0)) in each patient. Meanwhile, no serious postoperative complications occurred in all patients. The mean HOS-Sports subscale of patients increased from 71.0 (SD 5.3) to 94.83 (SD 4.24) at six months postoperatively (p < 0.001). The follow-up outcomes from all patients were "good" and "excellent", based on objective assessments. Conclusion: Preoperative MRN analysis can be used to facilitate the determination of the relationship between contracture band and normal tissues. The minimally invasive surgical design via MRN can avoid nerve damage and improve the release effect.

A cross-sectional study of non-suicidal self-injury in adults with depressive disorder: Associations with inflammation and cardiac structure and function.

OBJECTIVE: Non-suicidal self-injury (NSSI) is associated with cardiovascular disease (CVD), whereas inflammation is associated with both CVD and NSSI. However, few studies have investigated the correlation among NSSI, inflammation, and cardiac structure and function in CVD-free adult patients with depressive disorders. METHODS: We recruited 88 CVD-free adult patients with depressive disorders and 37 healthy individuals. Patients were divided into NSSI (n = 21) and non-NSSI (n = 67) groups based on the presence or absence of NSSI. Healthy individuals comprised the controls (n = 37). Echocardiography was applied to assess cardiac structure and function, and C-reactive protein (CRP) levels were measured to indicate inflammation. RESULTS: Compared with controls, the NSSI group exhibited a larger left ventricular end-systolic diameter (LVESD) and smaller left ventricular ejection fraction (LVEF). Left ventricular end-systolic volume (LVESV) was larger in the NSSI group than in the non-NSSI group. The CRP levels were higher in the NSSI group than in the non-NSSI group; however, this difference was not statistically significant. NSSI was positively associated with LVESD (ß = 1.928, p = 0.006) and LVESV (ß = 5.368, p = 0.003), negatively correlated with LVEF (ß = -2.600, p = 0.029), and positively correlated with CRP levels (ß = 0.116, p = 0.004). CRP levels did not mediate the association between NSSI and cardiac structure and function. CONCLUSIONS: This study indicated that NSSI was associated with left ventricular structure, systolic function, and inflammation, but CRP did not mediate the relationship between NSSI and echocardiogram parameters.

Abalone shell-derived Mg-doped mesoporous hydroxyapatite microsphere drug delivery system loaded with icariin for inducing apoptosis of osteosarcoma cells.

Hydroxyapatite (HAP) porous microspheres with very high specific surface area and drug loading capacity, as well as excellent biocompatibility, have been widely used in tumour therapy. Mg2+ is considered to be a key factor in bone regeneration, acting as an active agent to stimulate bone and cartilage formation, and is effective in accelerating cell migration and promoting angiogenesis, which is essential for bone tissue repair, anti-cancer, and anti-infection. In this study, abalone shells from a variety of sources were used as raw materials, and Mg2+-doped abalone shell-derived mesoporous HAP microspheres (Mg-HAP) were prepared by hydrothermal synthesis as Mg2+/ icariin smart dual delivery system (ICA-Mg-HAP, IMHA). With increasing of Mg2+ doping, the surface morphology of HAP microspheres varied from collapsed macroporous to mesoporous to smooth and non-porous, which may be due to Mg2+ substitution or coordination in the HAP lattice. At 30% Mg2+ doping, the Mg-HAP microspheres showed a more homogeneous mesoporous morphology with a high specific surface area (186.06 m2/g). The IMHA microspheres showed high drug loading (7.69%) and encapsulation rate (83.29%), sustained Mg2+ release for more than 27 days, sustained and stable release of icariin for 60 hours, and good responsiveness to pH (pH 6.4 > pH 5.6). In addition, the IMHA delivery system stimulated the rapid proliferation of bone marrow mesenchymal stem cells and induced apoptosis in MG63 cells by blocking the G2 phase cycle of osteosarcoma cells and stimulating the high expression of apoptotic genes (Bcl-2, caspase-3, -8, -9). This suggests that the abalone shell-based IMHA may have potential applications in drug delivery and tumour therapy.

Abalone shells bioenhanced carboxymethyl chitosan/collagen/PLGA bionic hybrid scaffolds achieving biomineralization and osteogenesis for bone regeneration.

Inspired by the formation of natural abalone shells (AS) similar to calcium salt deposition in human orthodontics, AS is used as an emulsifier in the scaffold to solve the problem of coexistence of natural and synthetic polymers and promote new bone formation. In this study, AS-stabilized and reinforced carboxymethyl chitosan/collagen/PLGA porous bionic composite scaffolds (AS/CMCS/Col/PLGA) were fabricated through the emulsion polymerization and bionic hybrid technology. As the addition of AS increased from 0.75 to 3.0 wt%, homogeneous distribution of flower-like particles could be observed on the inner surface of the scaffold, and its mechanical properties were improved. Particularly, 3.0 wt% AS-doped scaffolds (S3 and C + S3) exhibited excellent inorganic mineral deposition and osteoblast proliferation and differentiation abilities in vitro. In a SD rat calvarial defect model, they effectively promoted new bone formation in the defect and accelerated expression of osteogenic-angiogenic related proteins (COLI, OCN, VEGF). By virtue of its combined merits including good mechanical properties, inducing mineralization crystallization and facilitating osteogenesis, the 3.0 wt% AS-doped scaffold promises to be employed as a novel bone repair material for bone tissue regeneration.

Asymmetric chitosan-derivative/carboxymethylcellulose layer-by-layer film combining antimicrobial and vascular regeneration for the repair of infected wounds.

Bacterially infected wounds are a serious threat to patients' lives and health, and multifunctional dressings with antimicrobial properties and healing promotion are urgently needed. Thus, we used the cationic and anionic properties of chitosan (CS)-nerol (N) derivative (CSN) and carboxymethylcellulose (CMC) to prepare asymmetric layer-by-layer self-assembled (LBL) composite films (CSN-CMC LBL films) with antibacterial and healing properties using a spin-coating method. SEM images showed that the CSN-CMC LBL films had completely different degrees of roughness at the bottom (hydrophilic layer) and at the top (hydrophobic layer), with the roughness at the top increasing as the number of layers increased. The CSN and CMC were used to prepare asymmetric LBL films via the electrostatic attraction of -COO- and NH3+. In addition, adhesion and water contact angle tests showed that the CSN-CMC LBL films had enhanced tissue adhesion and good hydrophobicity. These materials had excellent antimicrobial activity and good biocompatibility. Importantly, the animal infection model results showed that CSN-CMC-8 LBL films effectively eliminated the infection in vivo, inhibited inflammation, promoted vascular regeneration, accelerated the epithelialization process, and achieved high quality healing. Overall, the CSN-CMC LBL films in this study showed considerable potential for application in infected wound healing.

Self-Healing Conductive Hydrogels with Dynamic Dual Network Structure Accelerate Infected Wound Healing via Photothermal Antimicrobial and Regulating Inflammatory Response.

Wound infections are an escalating clinical challenge with continuous inflammatory response and the threat of drug-resistant bacteria. Herein, a series of self-healing conductive hydrogels were designed based on carboxymethyl chitosan/oxidized sodium alginate/polymerized gallic acid/Fe3+ (CMC/OSA/pGA/Fe3+, COGFe) for promoting infected wound healing. The Schiff base and catechol-Fe3+ chelation in the dynamical dual network structure of the hydrogels endowed dressings with good toughness, conductivity, adhesion, and self-healing properties, thus flexibly adapting to the deformation of skin wounds. In terms of ultraviolet (UV) resistance and scavenging of reactive oxygen species (ROS), the hydrogels significantly reduced oxidative stress at the wound site. Additionally, the hydrogels with photothermal therapy (PTT) achieved a 95% bactericidal rate in 5 min of near-infrared (NIR) light radiation by disrupting the bacterial cell membrane structure through elevated temperature. Meanwhile, the inherent antimicrobial properties of GA could reduce healthy tissue damage caused by excessive heat. The composite hydrogels could effectively promote the proliferation and migration of fibroblasts and possess good biocompatibility and hemostatic effect. In full-thickness infected wound repair experiments in rats, the COGFe5 hydrogel combined with NIR effectively killed bacteria, modulated macrophage polarization (M1 to M2 phenotype) to improve the immune microenvironment of the wound, and shortened the repair time by accelerating the expression of collagen deposition (TGF-ß) and vascular factors (CD31). This combined therapy might provide a prospective strategy for infectious wound treatment.