Advanced application of carbohydrate-based micro/nanoparticles for rheumatoid arthritis.

Rheumatoid arthritis (RA) is a kind of synovitis and progressive joint destruction disease. Dysregulated immune cell activation, inflammatory cytokine overproduction, and subsequent reactive oxidative species (ROS) production contribute to the RA process. Carbohydrates, including cellulose, chitosan, alginate and dextran, are among the most abundant and important biomolecules in nature and are widely used in biomedicine. Carbohydrate-based micro/nanoparticles(M/NPs) as functional excipients have the ability to improve the bioavailability, solubility and stability of numerous drugs used in RA therapy. For on-demand therapy, smart reactive M/NPs have been developed to respond to a variety of chemical and physical stimuli, including light, temperature, enzymes, pH and ROS, alternating their physical and macroscopic properties, resulting in innovative new drug delivery systems. In particular, advanced products with targeted dextran or hyaluronic acid are exploiting multiple beneficial properties at the same time. In addition to those that respond, there are promising new derivatives in development with microenvironment and chronotherapy effects. In this review, we provide an overview of these recent developments and an outlook on how this class of agents will further shape the landscape of drug delivery for RA treatment.

Moving grating-based laser heterodyne digital holographic microscopy system for measuring dynamic phase of living cell attachment.

We propose a laser heterodyne digital holography microscopy system based on a moving grating, which uses the Doppler principle between a moving grating and beam to achieve a low-frequency bias between the diffracted beams, abandoning traditional heterodyne digital holography that requires multiple acousto-optic modulators. The dynamic phase distribution obtained using the laser heterodyne digital holography phase-reconstruction algorithm was more realistic and analyzable than the results of the angular spectrum algorithm. The structure and algorithm were used to capture the shape characteristics of mouse fibroblasts after ~2 h of incubation (37°C, 5% CO2), and the dynamic phase distribution of the cells was monitored in real-time during the attachment process. The system proposed in this study, with its high spatial resolution and high-precision phase measurement capability, is suitable for both static and live cells.

Non-coding RNAs in diabetic foot ulcer- a focus on infected wounds.

Diabetes mellitus is associated with a wide range of neuropathies, vasculopathies, and immunopathies, resulting in many complications. More than 30% of diabetic patients risk developing diabetic foot ulcers (DFUs). Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), play essential roles in various biological functions in the hyperglycaemic environment that determines the development of DFU. Ulceration results in tissue breakdown and skin barrier scavenging, thereby facilitating bacterial infection and biofilm formation. Many bacteria contribute to diabetic foot infection (DFI), including Staphylococcus aureus (S. aureus) et al. A heterogeneous group of "ncRNAs," termed small RNAs (sRNAs), powerfully regulates biofilm formation and DFI healing. Multidisciplinary foot care interventions have been identified for nonhealing ulcers. With an appreciation of the link between disease processes and ncRNAs, a novel therapeutic model of bioactive materials loaded with ncRNAs has been developed to prevent and manage diabetic foot complications.

Antisense yycF and BMP-2 co-delivery gelatin methacryloyl and carboxymethyl chitosan hydrogel composite for infective bone defects regeneration.

Repairing infected bone defects remains a challenge in clinical work. Intractable bacterial infections and insufficient osseointegration are major concerns for infected bone defects. To address these issues, we developed a gelatin methacryloyl (GelMA) and carboxymethyl chitosan (CMCS) composite hydrogel with BMP-2 growth factor and GO based antisense technology supported by a PLGA spring. In vitro, photo-crosslinked GelMA composite hydrogels shown excellent biocompatibility and degradability. Relying on the release of BMP-2 from the composite hydrogel provides osteogenic effects. The antisense yycF and BMP-2 were released with the degradation of GelMA and CMCS composite hydrogel. In terms of antimicrobial properties, CMCS, GO and post-transcriptional regulatory antisense yycF from the composite hydrogel synergistically kill S. aureus. In vivo, we implanted the composite hydrogel in a rat model of S. aureus infected femur defect, effectively accelerating bone healing in an infectious microenvironment. This research provides a novel biomaterial that is both antimicrobial and promotes bone regeneration, with the potential to treat infected bone defects.

[Short-term effectiveness of INBONE TM â ¡ total ankle prosthesis arthroplasty in the treatment of moderate to severe varus-type ankle arthritis].

Objective: To investigate the short-term effectiveness of INBONE TM Ⅱ total ankle prosthesis arthroplasty in the treatment of moderate to severe varus-type ankle arthritis. Methods: The clinical and radiographic data of patients with moderate to severe varus-type ankle arthritis, who were admitted between May 2017 and November 2021 and treated with total ankle arthroplasty (TAA) using INBONE TM Ⅱ prosthesis, was retrospectively analyzed. A total of 58 patients (58 ankles) met the selection criteria and were included in the study. Among them, there were 24 males and 34 females, with an average age of 62.6 years (range, 41-85 years). According to the preoperative tibiotalar angle (TTA), the patients were divided into a moderate varus group (group A, TTA 5°-15°, n=34) and a severe varus group (group B, TTA>15°, n=24). There was no significant difference in gender, side, etiology, preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score, ankle dorsiflexion, plantarflexion, and total range of motion, and tibial lateral surface angle (TLS) between the two groups ( P>0.05). Yet the patients in group A were younger than group B, the degrees of oesteoarthritis (Takakura stage) and ankle pain [visual analogue scale (VAS) score] were milder, and the TTA, talar tilt angle (TT), hindfoot alignment angle (HAA) were smaller while the tibial articular surface angle (TAS) was larger, showing significant differences ( P<0.05). The pre- and post-operative VAS score, AOFAS score, the occurrence of early and late complications, the radiographic parameters of the ankle (TTA, TAS, TT, HAA, TLS), ankle dorsiflexion, plantarflexion, and total range of motion were recorded and compared. Results: All patients were followed up 19-72 months, with an average of 38.9 months. Compared with the preoperative data, the VAS score of all patients significantly decreased ( P<0.05); the AOFAS score, ankle dorsiflexion range of motion, and total range of motion significantly increased ( P<0.05); and the TTA, TAS, TT, HAA, and TLS significantly improved at last follow-up ( P<0.05); but there was no significant difference in plantarflexion range of motion ( P>0.05). Early complications occurred in 13 patients, and only 1 patient underwent revision surgery due to a larger size of the talar component. At last follow-up, there was no significant difference in the difference of clinical parameters before and after operation between the two groups ( P>0.05); there was a significant difference in the difference of other radiographic parameters ( P<0.05) except TLS. No significant difference in the incidence of complications between the two groups was found ( P>0.05). Conclusion: TAA using the INBONE TM Ⅱtotal ankle prosthesis is an effective treatment for moderate or severe varus-type ankle arthritis, and good clinical and radiographic results can be obtained. Correcting bony deformities and balancing soft tissue are the keys to successful surgery.

Accelerated Healing of Infected Diabetic Wounds by a Dual-Layered Adhesive Film Cored with Microsphere-Loaded Hydrogel Composite Dressing.

Diabetic wounds, a prevalent chronic disease, are associated with older age. The hyperglycemic microenvironment in diabetic wounds significantly reduces the immune system, inducing bacterial invasion. The coupling of tissue repair and antibacterial treatment is critical for infected diabetic ulcer regeneration. In this study, a dual-layered sodium alginate/carboxymethyl chitosan (SA/CMCS) adhesive film cored with an SA-bFGF microsphere-loaded small intestine submucosa (SIS) hydrogel composite dressing with a graphene oxide (GO)-based antisense transformation system was developed to promote infected diabetic wound healing and bacterial eradication. Initially, our injectable SIS-based hydrogel composite stimulated angiogenesis, collagen deposition, and immunoregulation in diabetic wound repair. The GO-based transformation system subsequently inhibited bacterial viability in infected wounds by post-transformation regulation. Meanwhile, the SA/CMCS film provided stable adhesion covering the wound area to maintain a moist microenvironment, which promoted in situ tissue repair. Our findings provide a promising clinical translation strategy for promoting the healing of infected diabetic wounds.

The Regulations of Essential WalRK Two-Component System on Enterococcus faecalis.

Enterococcus faecalis (E. faecalis) is a Gram-positive, facultative anaerobic bacterium that is highly adaptable to its environment. In humans, it can cause serious infections with biofilm formation. With increasing attention on its health threat, prevention and control of biofilm formation in E. faecalis have been observed. Many factors including polysaccharides as well as autolysis, proteases, and eDNA regulate biofilm formation. Those contributors are regulated by several important regulatory systems involving the two-component signal transduction system (TCS) for its adaptation to the environment. Highly conserved WalRK as one of 17 TCSs is the only essential TCS in E. faecalis. In addition to biofilm formation, various metabolisms, including cell wall construction, drug resistance, as well as interactions among regulatory systems and resistance to the host immune system, can be modulated by the WalRK system. Therefore, WalRK has been identified as a key target for E. faecalis infection control. In the present review, the regulation of WalRK on E. faecalis pathogenesis and associated therapeutic strategies are demonstrated.

CodY is modulated by YycF and affects biofilm formation in Staphylococcus aureus.

Background: Staphylococcus aureus (S. aureus) is the leading cause of various infective diseases, including topical soft tissue infections. The goals of this study were to investigate the roles of YycF and CodY in the regulation of biofilm formation and pathogenicity. Methods: Electrophoretic mobility shift assay (EMSA) was conducted to validate the bound promoter regions of YycF protein. We constructed the codY up-regulated or down-regulated S. aureus mutants. The biofilm biomass was determined by crystal violet microtiter assay and scanning electron microscopy (SEM). Quantitative RT-PCR analysis was used to detect the transcripts of biofilm-related genes. The live and dead cells of S. aureus biofilm were also investigated by confocal laser scanning microscopy (CLSM). We constructed an abscess infection in Sprague Dawley (SD) rat models to determine the effect of CodY on bacterial pathogenicity. We further used the RAW264.7, which were cocultured with S. aureus, to evaluate the effect of CodY on macrophages apoptosis. Result: Quantitative RT-PCR analyses reveled that YycF negatively regulates codY expression. EMSA assays indicated that YycF protein directly binds to the promoter regions of codY gene. Quantitative RT-PCR confirmed the construction of dual- mutant stains codY + ASyycF and codY-ASyycF. The SEM results showed that the biofilm formation in the codY + ASyycF group was sparser than those in the other groups. The crystal violet assays indicated that the codY + ASyycF group formed less biofilms, which was consistent with the immunofluorescence results of the lowest live cell ration in the codY + ASyycF group. The expression levels of biofilm-associated icaA gene were significantly reduced in the codY + strain, indicating codY negatively regulates the biofilm formation. Furthermore, CodY impedes the pathogenicity in a rat-infection model. After cocultured with bacteria or 4-h in vitro, the apoptosis rates of macrophage cells were lowest in the codY + group. Conclusions: YycF negatively regulate the expression of codY. By interaction with codY, YycF could modulate S. aureus biofilm formation via both eDNA- dependent and PIA- dependent pathways, which can be a significant target for antibiofilm. CodY not only impedes the pathogenicity but also has a role on immunoregulation. Thus, the current evidence may provide a supplementary strategy for managing biofilm infections.

Antibacterial performance of graphene oxide/alginate-based antisense hydrogel for potential therapeutic application in Staphylococcus aureus infection.

Staphylococcus aureus (S. aureus) is an opportunistic bacterium that causes several infections in humans. However, chronic biofilms remain a major challenge associated with recalcitrance toward traditional treatments. Herein, an antibacterial hydrogel composed of antisense DNA oligonucleotides, graphene oxide and alginate is construed for biofilm management and infection care. The hydrogel is established through noncovalent binding and possesses injectability and degradability properties. Furthermore, hydrogels present controllable release of cargoes, genetic targeting antibacterial effects and stem cell supporting capabilities. Our in vivo results reveal a high antibiofilm performance and good biocompatibility, which significantly improve tissue regeneration. The hydrogel inhibits biofilm formation by decreasing the expression of YycFG with antisense and viability of strains by graphene oxide. Thus, antisense hydrogels can be a promising antibacterial bioactive material for potential therapeutic S. aureus infection.

Mini Review Therapeutic Strategies Targeting for Biofilm and Bone Infections.

Bone infection results in a complex inflammatory response and bone destruction. A broad spectrum of bacterial species has been involved for jaw osteomyelitis, hematogenous osteomyelitis, vertebral osteomyelitis or diabetes mellitus, such as Staphylococcus aureus (S. aureus), coagulase-negative Staphylococcus species, and aerobic gram-negative bacilli. S. aureus is the major pathogenic bacterium for osteomyelitis, which results in a complex inflammatory response and bone destruction. Although various antibiotics have been applied for bone infection, the emergence of drug resistance and biofilm formation significantly decrease the effectiveness of those agents. In combination with gram-positive aerobes, gram-negative aerobes and anaerobes functionally equivalent pathogroups interact synergistically, developing as pathogenic biofilms and causing recurrent infections. The adhesion of biofilms to bone promotes bone destruction and protects bacteria from antimicrobial agent stress and host immune system infiltration. Moreover, bone is characterized by low permeability and reduced blood flow, further hindering the therapeutic effect for bone infections. To minimize systemic toxicity and enhance antibacterial effectiveness, therapeutic strategies targeting on biofilm and bone infection can serve as a promising modality. Herein, we focus on biofilm and bone infection eradication with targeting therapeutic strategies. We summarize recent targeting moieties on biofilm and bone infection with peptide-, nucleic acid-, bacteriophage-, CaP- and turnover homeostasis-based strategies. The antibacterial and antibiofilm mechanisms of those therapeutic strategies include increasing antibacterial agents' accumulation by bone specific affinity, specific recognition of phage-bacteria, inhibition biofilm formation in transcription level. As chronic inflammation induced by infection can trigger osteoclast activation and inhibit osteoblast functioning, we additionally expand the potential applications of turnover homeostasis-based therapeutic strategies on biofilm or infection related immunity homeostasis for host-bacteria. Based on this review, we expect to provide useful insights of targeting therapeutic efficacy for biofilm and bone infection eradication.

Evaluation and Management of Cavus Foot in Adults: A Narrative Review.

OBJECTIVE: Cavus foot is a deformity defined by the abnormal elevation of the medial arch of the foot and is a common but challenging occurrence for foot and ankle surgeons. In this review, we mainly aim to provide a comprehensive evaluation of the treatment options available for cavus foot correction based on the current research and our experience and to highlight new technologies and future research directions. METHODS: Searches on the PubMed and Scopus databases were conducted using the search terms cavus foot, CMT (Charcot-Marie-Tooth), tendon-transfer, osteotomy, and adult. The studies were screened according to the inclusion and exclusion criteria, and the correction of cavus foot was analyzed based on the current research and our own experience. At the same time, 3D models were used to simulate different surgical methods for cavus foot correction. RESULTS: A total of 575 papers were identified and subsequently evaluated based on the title, abstract, and full text. A total of 84 articles were finally included in the review. The deformities involved in cavus foot are complex. Neuromuscular disorders are the main etiologies of cavus foot. Clinical evaluations including biomechanics, etiology, classification, pathophysiology and physical and radiological examinations should be conducted carefully in order to acquire a full understanding of cavus deformities. Soft-tissue release, tendon-transfer, and bony reconstruction are commonly used to correct cavus foot. Surgical plans need to be customized for different patients and usually involve a combination of multiple surgical procedures. A 3D simulation is helpful in that it allows us to gain a more intuitive understanding of various osteotomy methods. CONCLUSION: The treatment of cavus foot requires us to make personalized operation plans according to different patients based on the comprehensive evaluation of their deformities. A combination of soft-tissue and bony procedures is required. Bony procedures are indispensable for cavus correction. With the promotion of digital orthopedics around the world, we can use computer technology to design and implement cavus foot operations in the future.

Simultaneous Total Ankle Replacement and Contralateral Ankle Arthrodesis for Bilateral Ankle Osteoarthritis: A Retrospective Study Focused on Clinical Outcomes and Cost-effectiveness.

OBJECTIVE: Total ankle replacement (TAR) and ankle arthrodesis (AA) are two common surgical treatment options for end-stage ankle osteoarthritis. However, few reports compare the outcomes of simultaneous TAR and contralateral AA for bilateral ankle osteoarthritis. The aim of this study was to assess changes in pain, joint range of movement (ROM), functional outcomes, patient satisfaction, and cost-effectiveness following simultaneous TAR and contralateral AA. METHODS: A retrospective study was conducted on 12 patients with bilateral end-stage ankle osteoarthritis who underwent simultaneous TAR and contralateral AA in our institution between May 2016 and August 2018, and who had a minimum of two-year follow-up data. Clinical and radiological follow-up data for all patients were collected after 4 months, 1 year and 2 years. The results were assessed clinically on a visual analogue scale (VAS) and included ROM, American Orthopedic Foot and Ankle Society (AOFAS) ankle hindfoot score, and satisfaction questionnaire. The total hospital costs of patients were also recorded. Independent sample t tests were conducted to compare continuous variables between groups. Paired sample t-tests were conducted to compare changes from the preoperative to postoperative evaluations within each group. RESULTS: Both surgical groups presented with pain reduction (P < 0.001) at the one-year postoperative session, which was generally consistent until the two-year follow-up. There was a significant increase (P < 0.001) in the mean AOFAS score postoperatively in both ankles. The functional outcomes at the one- and two-year follow-up were significantly better in patients in the TAR group than in those in the AA group (P < 0.001). Joint ROM differences were observed between the two groups after surgery (decreased ankle ROM in arthrodesis, P < 0.001; increased ankle ROM in arthroplasty, P < 0.001). The mean satisfaction score was 2 (range, 1-4) for the TAR group and 3 (range, 1-5) for the AA group. A significant difference in the satisfaction score was observed between the two groups (P = 0.036). Simultaneous TAR and contralateral AA was 34.1% less expensive than simultaneous bilateral TAR. No intraoperative complications were noted in either group. Wound healing occurred without problems within 2 weeks after surgery. No symptomatic deep venous thrombosis was found during follow-up. CONCLUSION: TAR had better patient-perceived post-operative function and preserves more anatomic sagittal plane motion compared to ankles undergoing AA. In addition, simultaneous TAR and contralateral AA are more cost-effective than simultaneous bilateral TAR, with lower costs for the average patient.

Flexible Wearable Pressure Sensor Based on Collagen Fiber Material.

Flexible wearable pressure sensors play a pivotal role in healthcare monitoring, disease prevention, and humanmachine interactions. However, their narrow sensing ranges, low detection sensitivities, slow responses, and complex preparation processes restrict their application in smart wearable devices. Herein, a capacitive pressure sensor with high sensitivity and flexibility that uses an ionic collagen fiber material as the dielectric layer is proposed. The sensor exhibits a high sensitivity (5.24 kPa-1), fast response time (40 ms), long-term stability, and excellent repeatability over 3000 cycles. Because the sensor is resizable, flexible, and has a simple preparation process, it can be flexibly attached to clothes and the human body for wearable monitoring. Furthermore, the practicality of the sensor is proven by attaching it to different measurement positions on the human body to monitor the activity signal.

Osteochondral autograft transplantation in the treatment of AO/OTA type C3 tibial plafond fractures with irreducibly comminuted area and/or cartilage delamination in the distal tibial facet.

INTRODUCTION: Tibial plafond fractures, especially the AO/OTA type C3 ones that take place in young patients with excessive facet fragmentation and cartilage loss that preclude anatomical reduction and effective internal fixation, are devastating situations that often subject to primary arthrodesis. The aim of the current study is to introduce a joint preserving technique by using osteochondral autograft to treat such difficult cases and to evaluate its short-term outcome. METHODS: A total of 11 patients suffering AO-OTA type C3 tibial plafond fractures with irreparable area treated with osteochondral autograft and ORIF, with an average follow-up period of 34 months, were analyzed. Visual analogue scale (VAS), short-form 36 (SF-36), American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, and ankle range of motion (ROM) were assessed for functional outcome evaluation. The weight-bearing AP and lateral radiograph, as well as CT reconstructive images were examined to evaluate bony union and the occurrence of post-traumatic arthritis. RESULTS: At the final follow-up, the mean VAS scale was 2.2. The mean AOFAS and SF-36 scores were 86.3 and 84.5 respectively. Among all the included patients, 8 achieved both AOFAS and SF-36 scores above 80. The average ankle range of motion was 29.9°. No infection, compartment syndrome, post-traumatic arthrosis or donor site pain was noted in the current study. No patient received secondary ankle arthrodesis at the end of the follow-up. CONCLUSIONS: Although primary ankle arthrodesis is an effective method, routine ankle arthrodesis should be carried out with second thoughts in patients, especially patients with relatively young age, suffering AO-OTA type C3 tibial plafond fractures with irreducible area. On the other hand, osteochondral autograft transplantation may provide a chance to relieve pain without sacrificing the joint.

Primary Ewing sarcoma/peripheral primitive neuroectodermal tumors in the cranial bone and mobile spine: what is the difference?

BACKGROUND: Primary Ewing sarcoma (ES)/peripheral primitive neuroectodermal tumors (pPNETs) are aggressive bone tumors that rarely occur in the axial skeleton, including the cranial bone and mobile spine. The purpose of this study was to investigate whether there were any differences in patient characteristics, treatment strategies, and outcomes between patients with ES/pPNETs of the cranial bone and those with ES/pPNETs of the mobile spine. METHODS: A retrospective study was performed on 33 patients with ES/pPNETs who had been surgically treated and pathologically confirmed at our institution between 2010 and 2020. Patient characteristics were compared using Fisher exact tests or independent t tests. Survival rates were estimated via Kaplan-Meier survival analysis and compared using log-rank tests. RESULTS: Thirteen patients had ES/pPNETs of the cranial bone (39.4%), while 20 patients had ES/pPNETs of the mobile spine (60.6%). Patients with ES/pPNETs of the cranial bone had a younger mean age (14.8 vs 22.6 years; p = 0.047) and longer mean disease duration (2.5 vs 1.9 months; p = 0.008) compared with those of patients with ES/pPNETs of the mobile spine. Kaplan-Meier analysis showed that gross total resection (GTR) and radiotherapy resulted in a longer median survival time. The overall survival rates and progression-free survival rates of patients with ES/pPNETs of the cranial bone versus those of the mobile spine were not significantly different (p = 0.386 and p = 0.368, respectively). CONCLUSIONS: Patients with ES/pPNETs of the cranial bone were younger compared to patients with ES/pPNETs of the mobile spine. There was no significant difference in the prognosis of patients with ES/pPNETs of the cranial bone versus those of the mobile spine. Taken together, our findings suggest that GTR and radiotherapy offer the best prognosis for improved long-term survival.

The Role of Staphylococcus aureus YycFG in Gene Regulation, Biofilm Organization and Drug Resistance.

Antibiotic resistance is a serious global health concern that may have significant social and financial consequences. Methicillin-resistant Staphylococcus aureus (MRSA) infection is responsible for substantial morbidity and leads to the death of 21.8% of infected patients annually. A lack of novel antibiotics has prompted the exploration of therapies targeting bacterial virulence mechanisms. The two-component signal transduction system (TCS) enables microbial cells to regulate gene expression and the subsequent metabolic processes that occur due to environmental changes. The YycFG TCS in S. aureus is essential for bacterial viability, the regulation of cell membrane metabolism, cell wall synthesis and biofilm formation. However, the role of YycFG-associated biofilm organization in S. aureus antimicrobial drug resistance and gene regulation has not been discussed in detail. We reviewed the main molecules involved in YycFG-associated cell wall biosynthesis, biofilm development and polysaccharide intercellular adhesin (PIA) accumulation. Two YycFG-associated regulatory mechanisms, accessory gene regulator (agr) and staphylococcal accessory regulator (SarA), were also discussed. We highlighted the importance of biofilm formation in the development of antimicrobial drug resistance in S. aureus infections. Data revealed that inhibition of the YycFG pathway reduced PIA production, biofilm formation and bacterial pathogenicity, which provides a potential target for the management of MRSA-induced infections.

Novel nanographene oxide-calcium phosphate cement inhibits Enterococcus faecalis biofilm and supports dental pulp stem cells.

BACKGROUND: Enterococcus faecalis (E. faecalis) is the most recovered species from the root canals after failed root canal treatment. Calcium phosphate bone cement (CPC) scaffold is promising for applications in endodontic treatment as a kind of root canal sealer. Graphene oxide (GO) has been extensively considered as a kind of promising nano-materials for antibacterial applications. In the present study, an injectable CPC-chitosan paste containing GO was developed for promising endodontic therapy. The antibacterial properties of this paste against E. faecalis biofilms as well as the support for human dental pulp stem cells (hDPSCs) were investigated. METHODS: CPC-chitosan composite with or without GO injectable scaffold was fabricated. The hDPSC growth and viability on scaffolds were investigated by live/dead assay. Antibacterial effects against E. faecalis biofilms were determined in clinical detin block samples. RESULTS: The antibacterial CPC-chitosan-GO disks had excellent hDPSC support with the percentages of live cells at around 90%. CPC-chitosan-GO also had greater antibacterial activity on E. faecalis than that of CPC-chitosan control using detin block models (p < 0.05). CONCLUSIONS: The injectable CPC-chitosan-GO paste had strong effects on inhibition E. faecalis and hDPSC support, which could fill the void of adjusting paste to the defect and shaping in situ for promising endodontic therapy.

An Antisense yycF RNA Modulates Biofilm Organization of Methicillin-Resistant Staphylococcus aureus and Pathogenicity in a Rat Model of Osteomyelitis.

Staphylococcus aureus (S. aureus) is one of most common opportunistic pathogens and is attributed to several human infections. The increasing incidence of methicillin-resistant S. aureus (MRSA) is a serious clinical threat for osteomyelitis crisis. The YycFG two-component system of S. aureus regulates genes associated with biofilm formation. To investigate the potential role of an antisense yycF RNA in the regulation of transcription levels of yycF and associated effects on biofilm formation and pathogenicity, antisense yycF (ASyycF) RNA was detected by RT-PCR and 5' RACE assays. ASyycF overexpression mutants were constructed, and the biofilm biomass was determined by crystal violet microtiter assay and scanning electron microscopy (SEM). Quantitative RT-PCR and Western blotting analyses were used to detect whether ASyycF overexpression inhibited the transcription and translation of biofilm-related genes. Then, a rat tibial infective model was used to evaluate the pathogenicity of ASyycF overexpression in vivo. ASyycF transcription led to reductions in YycF production and biofilm formation. Overexpression of ASyycF inhibited the transcription and translation of biofilm-related genes. The sensitivity to vancomycin was improved in ASyycF-overexpressing MRSA. Furthermore, ASyycF inhibited MRSA invasion in a rat tibial infection model. From this study, the expression of the YycF protein was found to be inversely correlated with different levels of ASyycF transcription. The biofilm biomass and pathogenicity decreased in the ASyycF-overexpressing mutant. Thus, the current evidence may support ASyycF as a supplementary strategy for managing S. aureus and MRSA infections.

Antisense yycG modulates the susceptibility of Staphylococcus aureus to hydrogen peroxide via the sarA.

BACKGROUND: The infectious pathogen Staphylococcus aureus (S. aureus) is primarily associated with osteomyelitis. Hydrogen peroxide drainage is an effective antimicrobial treatment that has been adopted to combat S. aureus infections. Previous investigations have indicated that the antisense RNA (asRNA) strategy negatively modulates S. aureus YycFG TCS, and it significantly disrupts biofilm formation. However, the effects of the antisense yycG RNA (ASyycG) strategy on the susceptibility of biofilm-producing S. aureus to hydrogen peroxide and the mechanisms underlying this effect have not been elucidated to date. RESULTS: Overexpression of ASyycG inhibited the transcription of biofilm formation-related genes, including sarA and icaA. Additionally, the CFU counts and the live bacterial ratios of ASyycG biofilm-producing S. aureus treated with H2O2 were notably reduced across the groups. Notably, the predicted promoter regions of the sarA and icaA genes were directly regulated by YycF. CONCLUSIONS: ASyycG was observed to sensitize biofilm-producing S. aureus to H2O2 intervention synergistically via the sarA and thus may represent a supplementary strategy for managing osteomyelitis. However, future in-depth studies should attempt to replicate our findings in animal models, such as the rat osteomyelitis model.