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Abstract Retinal degenerative diseases are a leading cause of vision loss and blindness globally, impacting millions. These diseases result from progressive damage to retinal pigment epithelial (RPE) cells for which no curative or palliative treatments exist. Cell therapy, particularly RPE transplantation, has emerged as a promising strategy for vision restoration. This review provides a comprehensive overview of the recent advancements in clinical trials related to RPE transplantation. We discuss scaffold-free and scaffold-based approaches, including RPE cell suspensions and pre-organized RPE monolayers on biomaterial scaffolds. Key considerations, such as the form and preparation of RPE implants, delivery devices, strategies, and biodegradability of scaffolds, are examined. The article also explores the challenges and opportunities in RPE scaffold development, emphasising the crucial need for functional integration, immunomodulation, and long-term biocompatibility to ensure therapeutic efficacy. We also highlight ongoing efforts to optimise RPE transplantation methods and their potential to address retinal degenerative diseases.

Traditional optical waveguides or mediums are often silica-based materials, but their applications in biomedicine and healthcare are limited due to the poor biocompatibility and unsuitable mechanical properties. In term of the applications in human body, a biocompatible hydrogel system with excellent optical transparency and mechanical flexibility could be beneficial. In this review, we explore the different designs of hydrogel-based optical waveguides derived from natural and synthetic sources. We highlighted key developments such as light emitting contact lenses, implantable optical fibres, biosensing systems, luminating and fluorescent materials. Finally, we expand further on the challenges and perspectives for hydrogel waveguides to achieve clinical applications.

Polymeric nanofibers are attractive nanomaterials owing to their high surfacearea- to-volume ratio and superior flexibility but designing durable and recyclable polymer nanofibers is challenging. Here, the authors integrate the concept of covalent adaptable networks to produce dynamic covalently crosslinked nanofibers via electrospinning.

Designing nanocomposites with heterointerface as bifunctional electrocatalysts is a potential strategy to overcome the intrinsic activity limitation of electrocatalytic water splitting in acidic media, but it remains challenging. Herein, the highly efficient RuO2/Co3O4 electrocatalyst with a uniform nanoflower structure is prepared by hydrothermal growth combined with interface engineering. Benefiting from the unique nanostructure, the migration of electrons and intermediates is optimized by the sufficient exposure of abundant micropores and defects. Moreover, the formation of strong electronic interaction at the RuO2/Co3O4 heterointerfaces boosts the electrochemical active surface area and accelerates the reaction kinetics, which effectively improve the catalytic activity and stability of the catalyst. Based on enhanced intrinsic activity and electron transfer, the as‐synthesized RuO2/Co3O4 displays impressive hydrogen evolution reaction and oxygen evolution reaction activity, which respectively require low overpotentials of 240 and 100 mV to achieve a current density of 10 mA cm−2 in 0.5 m H2SO4. As a bifunctional electrode, RuO2/Co3O4 exhibits a low operating voltage of 1.58 V at 10 mA cm−2 for overall electrochemical water splitting. This study demonstrates the importance of heterostructure engineering in providing an avenue to achieve acid‐stable bifunctional electrocatalysts for energy conversion applications.

Reactive Oxygen Species (ROS) plays an important role in osteoarthritis (OA) development and progression. Here, a ROS-responsive nanocomposite scaffold called PPE@rGO-Pue was fabricated by electrospinning, wherein PCL served as the backbone, PEGDA-EDT as the ROS responsive motif, and rGO as puerarin (Pue) carrier. The electrospun nanofibers composed of PEGDA-EDT and rGO exhibits accelerated Pue release behavior in the response to H2O2 through dose-dependent manner in 2 weeks. The interactions of PEGDA-EDT and Pue dramatically inhibits ROS production and activates antioxidant enzymes such as CAT, GSS, SOD, and GSH. Furthermore, the expression of inflammatory factor IL-1β had decrease significantly. Subsequently, PPE@rGO-Pue had shown chondro-protective effect for OA, which was evidenced by the suppression of MMPs, resulting in matrix degradation and the increase of Col2a1 and GAG that attenuated the cartilage erosion. In summary, this ROS-responsive electrospun nanofibers with sustained release of Pue exhibited antioxidative, anti-inflammatory, and chondro-protective potentials, suggesting that it could be an excellent drug carrier for OA therapy. This work may shed light on the design of antioxidative biomaterials for OA.

Abstract Background Osteoarthritis (OA) is common musculoskeletal disorders associated with overgeneration of free radicals, and it causes joint pain, inflammation, and cartilage degradation. Lignin as a natural antioxidant biopolymer has shown its great potential for biomedical applications. In this work, we developed a series of lignin-based nanofibers as antioxidative scaffolds for cartilage tissue engineering. Results The nanofibers were engineered by grafting poly(lactic acid) (PLA) into lignin via ring-opening polymerization and followed by electrospinning. Varying the lignin content in the system was able to adjust the physiochemical properties of the resulting nanofibers, including fiber diameters, mechanical and viscoelastic properties, and antioxidant activity. In vitro study demonstrated that the PLA-lignin nanofibers could protect bone marrow-derived mesenchymal stem/stromal cells (BMSCs) from oxidative stress and promote the chondrogenic differentiation. Moreover, the animal study showed that the lignin nanofibers could promote cartilage regeneration and repair cartilage defects within 6 weeks of implantation. Conclusion Our study indicated that lignin-based nanofibers could serve as an antioxidant tissue engineering scaffold and facilitate the cartilage regrowth for OA treatment. Graphical Abstract

Lignin is a versatile biomass that possesses many different desirable properties such as antioxidant, antibacterial, anti-UV, and good biocompatibility. Natural lignin can be processed through several chemical processes. The processed lignin can be modified into functionalized lignin through chemical modifications to develop and enhance biomaterials. Thus, lignin is one of the prime candidate for various biomaterial applications such as drug and gene delivery, biosensors, bioimaging, 3D printing, tissue engineering, and dietary supplement additive. This review presents the potential of developing and utilizing lignin in the outlook of new and sustainable biomaterials. Thereafter, we also discuss on the challenges and outlook of utilizing lignin as a biomaterial.

Hydrogels composed from biomolecules have gained great interests as biomaterials for tissue engineering. However, their poor mechanical properties limit their application potential. Here, we synthesized a series of tough composite hydrogels from poly (vinyl alcohol) (PVA) and pectin for bone tissue engineering. With a balance of scaffold stiffness and pore size, PVA-Pec-10 hydrogel enhanced adhesion and proliferation of osteoblasts. The hydrogel significantly promoted osteogenesis in vitro by improving the alkaline phosphates (ALP) activity and calcium biomineralization, as well as upregulating the expressions of osteoblastic genes. The composite hydrogel also accelerated the bone healing process in vivo after transplantation into the femoral defect. Additionally, our study demonstrated that pectin and its Ca2+ crosslinking network play a crucial role of inducing osteogenesis through regulating the Ca2+/CaMKII and BMP-SMAD1/5 signaling. The optimized structure composition and multifunctional properties make PVA-Pec hydrogel highly promising to serve as a candidate for bone tissue regeneration.

Coating materials serve the purposes to protect, enhance and/or confer additional functionalities and properties to the underlying object surface or bulk materials. In recent years, nanotechnologies have been extensively incorporated into the functional coatings as manipulation of materials at the nanoscale can impart some unique chemical, mechanical, thermal, surface and photophysical properties that can be exploited to enhance functions required in urban built environments. In this review paper, recent research progresses of several categories of functional coatings were summarized with emphasis on their applications for green and smart buildings. These included hydrophobic coatings, hydrophilic and photocatalytic coatings, coatings for reduction in surface solar radiation as well as phase change materials (PCM) coatings. This review aims to provide a general introduction and research progress on these selected functional coating technologies, starting from the material's fabrication to its application when used in different building components.

Abstract Drug therapy of osteoarthritis (OA) is limited by the short retention and lacking of stimulus-responsiveness after intra-articular (IA) injection. The weak acid microenvironment in joint provides a potential trigger for controlled drug release systems in the treatment of OA. Herein, we developed an pH-responsive metal − organic frameworks (MOFs) system modified by hyaluronic acid (HA) and loaded with an anti-inflammatory protocatechuic acid (PCA), designated as MOF@HA@PCA, for the therapy of OA. Results demonstrated that MOF@HA@PCA could smartly respond to acidic conditions in OA microenvironment and gradually release PCA, which could remarkably reduce synovial inflammation in both IL-1β induced chondrocytes and the OA joints. MOF@HA@PCA also down-regulated the expression of inflammatory markers of OA and promoted the expression of cartilage-specific makers. This work may provide a new insight for the design of efficient nanoprobes for precision theranostics of OA .

Solvents are essential for chemical synthesis and material preparation; however, traditional solvents face challenges in meeting safety and sustainability standards. Consequently, there is a growing focus on environmentally friendly solvent systems for polymeric materials, with deep eutectic solvents (DESs) standing out as promising alternatives owing to their eco-friendly attributes. In this review, we summarize studies on this novel solvent system in a broad range of applications, where DESs play multiple roles in polymer synthesis and corresponding material fabrication. In detail, we focus on the utilization of DESs in the synthesis of green polymers and related functional polymeric materials ranging from soft materials such as gels and nanofibers to membranes, films, and complex architectures generated from various techniques such as 3D printing, electrospinning, and self-assembly, together with their properties. Moreover, we discuss the green credentials through sustainability analysis and life-cycle assessment of DES-based polymeric materials. We believe this review will inspire more investigation into the use of DESs for functional green polymeric materials towards a sustainable future. [ABSTRACT FROM AUTHOR]

Background: Rheumatoid arthritis (RA) is a chronic disabling inflammatory disease that causes synovial angiogenesis in an invasive manner and leads to joint destruction. Currently available pharmacotherapy for RA has unwanted side effects and limitations. Although anti-angiogenic therapy is regarded as a new potential treatment for RA, only a few anti-angiogenic drugs are available. An increasing number of studies have shown that β -sitosterol (BSS) may exert inhibitory effects against angiogenesis. However, the mechanisms involved are still unclear. Methods: Based on the results of the gene set enrichment analysis (GSEA) of the transcriptome data of endothelial cells from RA patients, we evaluated the pharmacological effects of BSS on the tube formation, cell proliferation, and migration of human umbilical vein endothelial cells (HUVECs). Furthermore, the effects of BSS treatment on vascular endothelial growth factor receptor 2 (VEGFR2) were determined using molecular docking and Western blotting. Additionally, in the presence or absence of BSS, synovial angiogenesis and joint destruction of the ankle were investigated in collagen-induced arthritis (CIA) mice. The effect of BSS treatment on VEGFR2/p-VEGFR2 expression was verified through immunohistochemical staining. Results: The immunohistochemistry results revealed that BSS treatment inhibited angiogenesis both in vitro and in vivo. In addition, the results of 5-ethynyl-2′-deoxyuridine and cell cycle analysis showed that BSS treatment suppressed the proliferation of HUVECs, while the Transwell migration and stress fiber assays demonstrated that BSS treatment inhibited the migration of HUVECs. Notably, the inhibitory effect of BSS treatment on VEGFR2/p-VEGFR2 was similar to that of axitinib. In CIA mice, BSS also exerted therapeutic effects on the ankles by reducing the degree of swelling, ameliorating bone and cartilage damage, preventing synovial angiogenesis, and inhibiting VEGFR2 and p -VEGFR2 expression. Conclusion: Therefore, our findings demonstrate that BSS exerts an inhibitory effect on synovial angiogenesis by suppressing the proliferation and migration of endothelial cells, thereby alleviating joint swelling and bone destruction in CIA mice. Furthermore, the underlying therapeutic mechanisms may involve the inhibition of VEGF signaling pathway activation. [ABSTRACT FROM AUTHOR]

Cationic polymers remain attractive tools for non-viral gene transfer. The effectiveness of these vectors rely on the ability to deliver plasmid DNA (pDNA) into the nucleus of cells.While we have previously demonstrated the potential of Lignin-PGEA-PEGMA as a non-viral gene delivery vector, alterations of cellular phenotype and cytotoxicity were observed post transfection. The present study aims to explore transfection conditions for high efficiency and low toxicity of the Lignin-PGEA-PEGMA based gene delivery system. Cellular toxicity was significantly reduced by using the centrifugation protocol, which enables rapid deposition of DNA complexes. Replacement of media post centrifugation resulted in minimal exposure of cells to excess polymers, which were toxic to cells. At an optimized DNA amount (500–750 ng) and molar ratios of nitrogen (N) in polymer to phosphate (P) in pDNA (N/P = 30–40), with the use of a novel transfection enhancer that facilitates endosomal escape and nuclear trafficking, the efficiency of gene delivery was increased significantly 24 h post transfection. The present study demonstrated an appropriately optimized protocol that enabled the utility of a novel cationic polymer blend with a mixture of fusogenic lipids and a histone deacetylate inhibitor in non-viral transfection, thereby providing an attractive alternative to costly commercial gene carriers. [ABSTRACT FROM AUTHOR]

To biosynthesize the (3R,5S)-CDHH in an industrial scale, a newly synthesized stereoselective short chain carbonyl reductase (SCR) was successfully cloned and expressed in Escherichia coli. The fermentation of recombinant E. coli harboring SCR was carried out in 500 L and 5000 L fermenters, with biomass and specific activity of 9.7 g DCW/L, 15749.95 U/g DCW, and 10.97 g DCW/L, 19210.12 U/g DCW, respectively. The recombinant SCR was successfully applied for efficient production of (3R,5S)-CDHH. The scale-up synthesis of (3R,5S)-CDHH was performed in 5000 L bioreactor with 400 g/L of (S)-CHOH at 30°C, resulting in a space-time yield of 13.7 mM/h/g DCW, which was the highest ever reported. After isolation and purification, the yield and d.e. of (3R,5S)-CDHH reached 97.5% and 99.5%, respectively. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:612-620, 2017 [ABSTRACT FROM AUTHOR]

Further developing on the technique originally intended for the purpose of forming tough hydrogels, we showed in thisstudy that the double-network system can also be used to synthesize an injectable gel. The gel was made up of poly (ethylene glycol) methyl ether methacrylate, sodium alginic acid, and calcium chloride, and two networks, consisting of ionic and covalent networks, were found to co-exist in the gel. Additionally, the rheology studies showed that the mechanical properties of the gel only deteriorated under high strain, demonstrating the robustness of the gel upon injection. The results of a cell cytotoxicity test and a preliminary cell encapsulation study were promising, showing good cell compatibility and thus suggesting that the hydrogels could potentially be used for cell delivery. [ABSTRACT FROM AUTHOR]

An injectable calcium phosphate cement (CPC) with porous structure and excellent anti-washout ability was developed in the study. Citric acid and sodium bicarbonate were added into the CPC powder consisting of tetracalcium phosphate (TTCP) and dicalcium phosphate dihydrate (DCPD) to form macro-pores, then different concentrations of sodium hyaluronate (NaHA) solution, as liquid phase, was added into the cement to investigate its effect on CPC’s performance. The prepared CPCs were tested on workability (injectable time and setting time), mechanical strength, as well as anti-washout ability. The experimental results showed that addition of NaHA not only enhanced the anti-washout ability of the CPC dramatically but also improve its other properties. When NaHA concentration was 0.6 wt%, the injectable time elongated to 15.7 ± 0.6 min, the initial and final setting times were respectively shorten to 18.3 ± 1.2 and 58.7 ± 2.1 min, and the compressive strength were increased to 18.78 ± 1.83 MPa. On the other hand, Addition of NaHA showed little effect on porous structure of the CPC and enhanced its bioactivity obviously, which was confirmed by the apatite formation on its surface after immersion in simulated body fluid (SBF). In conclusion, as an in situ shaped injectable biomaterials, the CPC with appropriate addition of NaHA would notably improve its performance and might be used in minimal invasive surgery for bone repair or reconstruction. [ABSTRACT FROM AUTHOR]

Abstract: The enhancement of hybridization efficiency of deoxyribonucleic acid (DNA) targets using oligonucleotide pre-hybridization is studied on two sequence-inversed micro-arrayed probes. The sequences for pre-hybridizing both oligo and target DNA are designed to be fully complementary with their shared DNA probe in a coaxial stacking configuration; i.e. they hybridize immediately alongside each other along the continuous complement probe strand. The pre-hybridizing oligo and target DNA are differentiated by being labeled with two distinct fluorescent dyes, and the cooperative effect on hybridization efficiency is investigated through the comparison of the stacking and individual hybridization configurations based on the detection signals of the labeling dyes. The results show that the pre-hybridization of a DNA oligo enhances the subsequent hybridization efficiency of the target-DNA coupling onto the same probe. The efficiency is enhanced if the hybridization position occurs at a site close to the substrate surface. [Copyright &y& Elsevier]

Background: Rheumatoid arthritis (RA) is a chronic disabling inflammatory disease that causes synovial angiogenesis in an invasive manner and leads to joint destruction. Currently available pharmacotherapy for RA has unwanted side effects and limitations. Although anti-angiogenic therapy is regarded as a new potential treatment for RA, only a few anti-angiogenic drugs are available. An increasing number of studies have shown that β-sitosterol (BSS) may exert inhibitory effects against angiogenesis. However, the mechanisms involved are still unclear.Methods: Based on the results of the gene set enrichment analysis (GSEA) of the transcriptome data of endothelial cells from RA patients, we evaluated the pharmacological effects of BSS on the tube formation, cell proliferation, and migration of human umbilical vein endothelial cells (HUVECs). Furthermore, the effects of BSS treatment on vascular endothelial growth factor receptor 2 (VEGFR2) were determined using molecular docking and Western blotting. Additionally, in the presence or absence of BSS, synovial angiogenesis and joint destruction of the ankle were investigated in collagen-induced arthritis (CIA) mice. The effect of BSS treatment on VEGFR2/p-VEGFR2 expression was verified through immunohistochemical staining.Results: The immunohistochemistry results revealed that BSS treatment inhibited angiogenesis both in vitro and in vivo. In addition, the results of 5-ethynyl-2′-deoxyuridine and cell cycle analysis showed that BSS treatment suppressed the proliferation of HUVECs, while the Transwell migration and stress fiber assays demonstrated that BSS treatment inhibited the migration of HUVECs. Notably, the inhibitory effect of BSS treatment on VEGFR2/p-VEGFR2 was similar to that of axitinib. In CIA mice, BSS also exerted therapeutic effects on the ankles by reducing the degree of swelling, ameliorating bone and cartilage damage, preventing synovial angiogenesis, and inhibiting VEGFR2 and p-VEGFR2 expression.Conclusion: Therefore, our findings demonstrate that BSS exerts an inhibitory effect on synovial angiogenesis by suppressing the proliferation and migration of endothelial cells, thereby alleviating joint swelling and bone destruction in CIA mice. Furthermore, the underlying therapeutic mechanisms may involve the inhibition of VEGF signaling pathway activation.

Schwann cell transplantation and hyperbaric oxygen therapy each promote recovery from spinal cord injury, but it remains unclear whether their combination improves therapeutic results more than monotherapy. To investigate this, we used Schwann cell transplantation via the tail vein, hyperbaric oxygen therapy, or their combination, in rat models of spinal cord contusion injury. The combined treatment was more effective in improving hindlimb motor function than either treatment alone; injured spinal tissue showed a greater number of neurite-like structures in the injured spinal tissue, somatosensory and motor evoked potential latencies were notably shorter, and their amplitudes greater, after combination therapy than after monotherapy. These findings indicate that Schwann cell transplantation combined with hyperbaric oxygen therapy is more effective than either treatment alone in promoting the recovery of spinal cord in rats after injury.

Objective: To investigate the efficacy of posterior axillary approach internal fixation for Ideberg Ⅰa andⅡ glenoid fractures., Methods: From December 2018 to September 2021, 9 patients with lower part of glenoid fractures were treated by posterior axillary approach, including 3 males and 6 females, aged from 50 to 78 years old. All the fractures were closed fractures. According to Ideberg type of scapular glenoid fracture was type Ⅰa in 6 cases and type Ⅱ in 3 cases. AP and lateral X-ray films of scapula were taken at 6, 12 weeks and 6 and 12 months postoperatively. Constant-Murley and disabilities of the arm shoulder and hand (DASH), and other complications were recorded at the latest follow-up., Results: Nine patients were followed up, ranged from 6 to 15 months. And bone healing was achieved in all 9 patients at the final follow-up, the healing time 3 to 6 months, Constant-Murley score at the final follow-up ranged from 55 to 96, and DASH score ranged from 3.33 to 33.33. Both of them were better than preoperative., Conclusion: The posterior axillary approach internal fixation for Ideberg Ⅰa and Ideberg Ⅱ Glenoid fractures scapular fracture is satisfactory and worthy of clinical application.

Background: Forearm crisscross injury is rare in children; there is no relevant literature so far. Surgeons lack experience and knowledge in treating this type of crisscross injury. We report a case of forearm crisscross injury in a child for the first time and analyze its mechanism., Case Summary: An 8-year-old boy experienced pain in his left forearm when he accidentally fell while skateboarding. Physical examination revealed swelling and deformity of the left forearm. We performed imaging and the results revealed left radial head dislocation, left distal radial epiphyseal separation from the shaft, and interruption of the continuity of the dorsal cortex of the left distal ulna. Anteroposterior and lateral X-ray films showed that the radius and ulna were crisscrossed. A diagnosis of superior radioulnar joint dislocation, left distal radial epiphyseal injury, and left distal ulnar fracture was made. After unsuccessful manual reduction, we adopted a minimally invasive procedure and succeeded. After a 14-wk period of follow-up, the patient had good left upper limb function, no complaints of pain or limited range of motion, and good follow-up results., Conclusion: This is the first report of a child with a forearm crisscross injury in which the mechanism and the differences from adult crisscross injury are analyzed. Minimally invasive surgery with intramedullary fixation can achieve a good therapeutic effect. This case provides a reference for the treatment of similar patients in the future., Competing Interests: Conflict-of-interest statement: The authors have nothing to disclose., (©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.)

World Health Organization estimated that heart failure initiated by coronary artery disease and myocardial infarction (MI) leads to 29 per cent of deaths worldwide. Heart failure is one of the leading causes of death in industrialized countries and is expected to become a global epidemic within the twenty-first century. MI, the main cause of heart failure, leads to a loss of cardiac tissue impairment of left ventricular function. The damaged left ventricle undergoes progressive 'remodelling' and chamber dilation, with myocyte slippage and fibroblast proliferation. Repair of diseased myocardium with in vitro-engineered cardiac muscle patch/injectable biopolymers with cells may become a viable option for heart failure patients. These events reflect an apparent lack of effective intrinsic mechanism for myocardial repair and regeneration. Motivated by the desire to develop minimally invasive procedures, the last 10 years observed growing efforts to develop injectable biomaterials with and without cells to treat cardiac failure. Biomaterials evaluated include alginate, fibrin, collagen, chitosan, self-assembling peptides, biopolymers and a range of synthetic hydrogels. The ultimate goal in therapeutic cardiac tissue engineering is to generate biocompatible, non-immunogenic heart muscle with morphological and functional properties similar to natural myocardium to repair MI. This review summarizes the properties of biomaterial substrates having sufficient mechanical stability, which stimulates the native collagen fibril structure for differentiating pluripotent stem cells and mesenchymal stem cells into cardiomyocytes for cardiac tissue engineering.

Objective: To investigate the inhibitory effect of the small interfering RNA targeting mdm2 gene on the growth of osteosarcoma cells., Methods: PGCsilencerTM-mdm2 siRNA was constructed and transfected into the osteosarcoma cell line U2OS cells. The inhibitory effects on mdm2 were determined by RT-PCR and Western blot analysis. The cell growth activity was determined by MTT assay, and the cell apoptosis was examined by flow cytometry. The therapeutic effects of simdm2 was assessed on the nude mouse model of transplanted tumor., Results: The simdm2 plasmid was successfully constructed. After simdm2 being transfected into the U2OS cells, the expressions of mdm2 gene and protein were significantly inhibited. The ability of cell growth activity decreased greatly and cell apoptosis occurred apparently. There was no significant difference between the negative control group and non-transfected group. The growth of xenograft tumor in simdm2 transfected nude mice was inhibited and the expressions of mdm2 gene and protein were down-regulated remarkably., Conclusion: siRNA targeting mdm2 gene inhibits the mdm2 expression in osteosarcoma U2OS cells and the growth of osteosarcoma in nude mice.