Colloids and Surfaces B: Biointerfaces最新文献

Large bone defects are a major clinical challenge in bone reconstructive surgery. 3D printing is a powerful technology that enables the manufacture of custom tissue-engineered scaffolds for bone regeneration. Electrical stimulation (ES) is a treatment method for external bone defects that compensates for damaged internal electrical signals and stimulates cell proliferation and differentiation. In this study, we propose a simple, reliable, and versatile strategy to prepare multifunctional 3D printed scaffold combined with ES for bone defect therapy. Firstly, scaffolds composed of polycaprolactone (PCL) and Ti₃C₂ were prepared by 3D printing technology, and then a stromal cell derived factor 1 (SDF1) containing DOPA tag was loaded onto the scaffold surface. Ti₃C₂ was selected as the electrode component because of its excellent electrical conductivity. The selection of DOPA-modified SDF-1(DOPA-SDF1) can improve the material binding ability and exert long-term stem cell recruitment function. The results show that prepared 3D printed scaffold (DOPA-SDF1@PCL#Ti₃C₂) has good hydrophilicity, electrical conductivity, antibacterial property, biocompatibility and stem cell recruitment ability. Furthermore, the expression of osteogenic specific genes in scaffold surface cells was significantly increased when pulse ES (PES) treatment was applied. The results of tibial plateau defect repair experiment showed that DOPA-SDF1@PCL#Ti₃C₂ scaffold can significantly promote the formation of new bone and collagen fibres. When the DOPA-SDF1@PCL#Ti₃C₂ scaffold was used in combination with PES therapy, the bone defect regeneration rate was further improved. This kind of scaffold could provide a new strategy for promoting the healing of large bone injuries and could expand the application of adjuvant therapy such as PES.

Traditional tissue engineering strategies focus on geometrically static tissue scaffolds, lacking the dynamic capability found in native tissues. The emerging field of 4D bioprinting offers a promising method to address this challenge. However, the requirement for consistent exogenous supplementation of growth factors (GFs) during tissue maturation poses a significant obstacle for in vivo application of 4D bioprinted constructs. We herein developed composite bioinks composed of photocrosslinkable, jammed alginate methacrylate (AlgMA) and gelatin methacrylate (GelMA), incorporating GelMA microspheres loaded with GFs to provide sustained local GF presentation over 50 days for 4D tissue bioprinting. The composite bioink exhibited excellent printability, enabling 3D printing with good accuracy (∼120 %) and fidelity (105 % - 114 %). By incorporating a photoabsorbent to enhance light attenuation, a gradient network along the light propagation pathway was generated, facilitating programmable and controllable 4D shape transformation. This process allowed the fabrication of complex living constructs with defined architectures through morphing. A proof-of-concept study on cartilage regeneration demonstrated the effectiveness of sustained GF presentation in driving tissue development, showing significant glycosaminoglycan production (GAG/DNA 10.3), and substantial upregulation of type II collagen (125.8-fold) and aggrecan (16.4-fold) mRNA expression, thereby eliminating the need for exogenous GF supplementation. This study underscores the transformative potential of integrating dynamic tissue scaffolding with sustained GF delivery, thereby addressing key limitations of traditional tissue engineering approaches and offering new avenues for tissue repair applications.

Numerous types of contemporary antibiotic treatment regimens have become ineffective with the increasing incidence of drug tolerance. As a result, it is pertinent to seek novel and innovative solutions such as antibacterial nanomaterials (NMs) for the prohibition and treatment of hazardous microbial infections. Unlike traditional antibiotics (e.g., penicillin and tetracycline), the unique physicochemical characteristics (e.g., size dependency) of NMs endow them with bacteriostatic and bactericidal potential. However, it is yet difficult to mechanistically predict or decipher the networks of molecular interaction (e.g., between NMs and the biological systems) and the subsequent immune responses. In light of such research gap, this review outlines various mechanisms accountable for the inception of drug tolerance in bacteria. It also delineates the primary factors governing the NMs-induced molecular mechanisms against microbes, specifically drug-resistant bacteria along with the various NM-based mechanisms of antibacterial activity. The review also explores future directions and prospects for NMs in combating drug-resistant bacteria, while addressing challenges to their commercial viability within the healthcare industry.

Polymethacrylate and its derivatives are widely used in food industry and biomedical applications for their plasticity, biocompatibility and optical transparency. However, susceptibility to bacterial growth on their surfaces limits their applications. In this study, linear and branched polyethyleneimine (PEI) molecules were grafted onto poly(ethyl methacrylate) (PEMA) via aminolysis using a simple one-step method to enhance the antibacterial properties of PEMA films. PEI-modified PEMA films were characterized by ATR-FTIR, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA). The modified films exhibited optimal bactericidal efficiency of 98.0 % against Escherichia coli (E. coli) and over 99.9 % against Staphylococcus aureus (S. aureus). Furthermore, hydrolysis was found to contribute to anchoring PEI onto PEMA as well. Though branched PEI exhibited a higher grafting amount than the linear ones under same conditions, PEMA modified with linear PEI presented a similar or even higher antibacterial efficiency than those grafted with branched PEI. Overall, PEI-grafted PEMA films prepared with simple one-step method exhibit effective antibacterial properties and good biocompatibilities, making them promising candidates for biomedical devices and other applications.

Traditional design approaches for nanozymes typically rely on empirical methods and trial-and-error, which hampers systematic optimization of their structure and performance, thus limiting the efficiency of developing innovative nanozymes. This study leverages machine learning techniques supported by high-throughput computations to effectively design nanozymes with multi-enzyme activities and to elucidate their reaction mechanisms. Additionally, it investigates the impact of dopants on the microphysical properties of nanozymes. We constructed a machine learning prediction framework tailored for dopant nanozymes exhibiting catalytic activities like to oxidase (OXD) and peroxidase (POD). This framework was used to evaluate key catalytic performance parameters, such as formation energy, density of states (DOS), and adsorption energy, through density functional theory (DFT) calculations. Various machine learning models were employed to predict the effects of different doping element ratios on the catalytic activity and stability of nanozymes. The results indicate that the combination of machine learning with high-throughput computations significantly accelerates the design and optimization of dopant nanozymes, providing an efficient strategy to address the complexities of nanozyme design. This approach not only boosts the efficiency and capability for innovation in material design but also provides a novel theoretical analytical avenue for the development of new functional materials.

Alpha-fetoprotein (AFP), serves as a reliable and vital biomarker for precise diagnosis and effective monitoring of hepatocellular carcinoma, requires precise detection. Herein, a sandwich-structured electrochemical immunosensor was crafted, employing three-dimensional layered porous carbon modified with gold nanoparticles (Au NPs) as the substrate and Au NPs/Cu₉S₈ as the labeling compound for accurate and sensitive detection of AFP. Due to the effective coordination between the 3D carbon network, Au NPs, and hollow Cu₉S₈ nanocubes, the sandwich-structured electrochemical immunosensor was able to produce three distinct response signals via various detection techniques, demonstrating a broad linear range (0.0001-400 ng/mL), exceptional sensitivity, and a remarkably low detection limit of 2.63 fg/mL. Moreover, the constructed immunosensor could be used to detect AFP in human serum. This research may offer a novel material framework for developing highly sensitive immunosensors.

Bacterial infection and inadequate osseointegration represent significant challenges in the application of titanium (Ti)-based bone implants. Surface modification presents a promising strategy to address these obstacles. Taking advantage of silver ions, black phosphorus nanosheets (BPNs) and polydopamine (PDA), this study developed a versatile platform on the surface of Ti-12Mo-10Zr (TMZ) alloy through a multiple surface modification process, including the anodic oxidation treatment of TMZ alloy, the preparation and addition of silver-loaded BPNs (BPNs/Ag), and the coating with PDA. Our results demonstrated that silver enhanced the stability of BPNs/Ag, which were successfully loaded to the nanostructure of oxidized TMZ surface. PDA coating conferred a pH-responsive property to the surface, prolonged the release of silver ions, and improved the photothermal performance. In acidic conditions that mimic bone defect microenvironment, the platform exhibited good photothermal performance, accelerated Ag⁺ release, enhanced antibacterial efficacy, and increased osteoinductivity. Taken together, due to its advantageous characteristics, the versatile platform provides a valuable solution to improve the surface performance of TMZ alloys.

Breast cancer remains one of the most prevalent and deadly cancers among women worldwide, necessitating the development of more effective and comprehensive treatment strategies. In this study, we successfully synthesized mesoporous polydopamine (MPDA) with photothermal effects for the co-delivery of the chemotherapeutic drug doxorubicin (DOX) and the immune adjuvant imiquimod (R837), resulting in the development of a multifunctional nanoplatforms termed MDR. MDR displayed excellent photothermal conversion efficiency and pH-responsive drug release behavior. In vitro assessments revealed significant cytotoxicity of MDR against 4T1 cells under 808 nm laser irradiation, with enhanced cellular uptake in both 4T1 cells and bone marrow-derived dendritic cells (BMDCs). Additionally, the expression levels of the costimulatory molecules CD80 and CD86 were remarkably higher in the MDR-treated group than free R837 after co-incubation with immature BMDCs, indicating a stronger ability to promote BMDC maturation and effectively stimulate immune response activation. Intratumoral injection in breast cancer-bearing mice further demonstrated that the MDR + NIR group significantly inhibited tumor growth compared to other groups, with no apparent side effects. In conclusion, the multifunctional nanoplatforms integrating photothermal therapy, chemotherapy, and immunotherapy are expected to provide a novel therapeutic approach for the multimodal treatment of breast cancer.

Background: Irresponsible and wholesale use of antimicrobial agents is the principal cause of the emergence of strains of resistant microorganisms to traditional drugs. Oligoventin is a neutral peptide isolated from spider eggs of Phoneutria nigriventer, with antimicrobial activity against Gram-positive, Gram-negative, and yeast organisms. However, the molecular target and pathways of antimicrobial activity are still unknown. Thus, the aim of the present study is to prospect receptors associated with the antimicrobial activity of Oligoventin using in silico tools.

Methods: The PharmMapper and PDB server was used to prospect targets originating from microorganisms. Additionally, the PatchDock server was utilized to perform molecular docking between Oligoventin and the targets. Subsequently, the I-TASSER server was adopted to predict the ligand site. Finally, the docking results and predicted sites were compared with literature sites of each target.

Results: Over 100 potential receptors for oligoventin have been identified. Among these, enoyl-ACP reductase (Id_pdb1LXC) and thymidylate synthase ThyX (Id_pdb 1O28) from bacteria and N-acetylglucosamine phosphate mutase (Id_pdb 2DKD) showed superior interaction with oligoventin, exhibiting colocalization between docked residues and cofactor/active sites. These enzymes play a crucial role in fatty acid and DNA biosynthesis in prokaryotes and in cell wall synthesis in yeast.

Conclusion: Therefore, in silico results suggest that Oligoventin can impair fatty acid DNA, cell wall synthesis, thereby reducing microbial proliferation and causing microorganism death.