Journal of Materials Chemistry B最新文献

Guided bone regeneration (GBR) is an extensively used technique for the treatment of maxillofacial bone defects and bone mass deficiency in clinical practice. However, to date, studies on membranes for GBR have not achieved the combination of suitable properties and cost-effective membrane production. Herein, we developed a polycaprolactone/human extracellular matrix-like collagen (PCL/hCol) membrane with an asymmetric porous structure via the nonsolvent-induced phase separation (NIPS) method, which is a highly efficient procedure with simple operation, scalable fabrication and low cost. This membrane possessed a porous rough surface, which is conducive to cell attachment and proliferation for guiding osteogenesis, together with a relatively smooth surface with micropores, which allows the passage of nutrients and is unfavorable for the adhesion of cells, thus preventing fibroblast invasion and overall meeting the demands for GBR. Besides, we evaluated the characteristics and biological properties of the membrane and compared them with those of commercially available membranes. Results showed that the PCL/hCol membrane exhibited excellent mechanical properties, degradation characteristics, barrier function, biocompatibility and osteoinductive potential. Furthermore, our in vivo study demonstrated the promotive effect of the PCL/hCol membrane on bone formation in rat calvarial defects. Taken together, our NIPS-prepared PCL/hCol membrane with promising properties and production advantages offers a new perspective for its development and potential use in GBR application.

The development of theranostic agents that offer complete biocompatibility, coupled with enhanced diagnostic and therapeutic performance, is crucial for fluorescence imaging-guided photothermal therapy in anti-tumor applications. However, the fabrication of nanotheranostics meeting the aforementioned requirements is challenged by concerns regarding biosafety and limited control over construction. Herein, we reported a class of fluorescence imaging-guided photothermal theranostic nanomaterials that are composed of amino acid derivatives and clinically used small photoactive indocyanine green molecules. Through manipulation of noncovalent interactions, these binary building blocks can co-assemble into nanoparticles in a tunable manner. Significantly, such construction not only maintained the fluorescence properties of photoactive molecules, but also enhanced their stability to overcome barriers from photodegradation and complex physiological conditions. These collective features integrated their precise anti-tumor applications, including fluorescence imaging diagnosis and photothermal ablation therapy. This study reported a class of nanotheranostics characterized by biocompatibility, adjustable construction, and robust stability, which are beneficial for the clinical translation of fluorescence imaging-guided photothermal therapy against tumors.

Chitosan bio-adhesives bond strongly with various biological tissues, such as skin, mucosa, and internal organs. Their adhesive ability arises from amino acid and hydroxyl groups in chitosan, facilitating interactions with tissue surfaces through chemical (ionic, covalent, and hydrogen) and physical (chain entanglement) bonding. As non-toxic, biodegradable, and biocompatible materials, chitosan bio-adhesives are a safe option for medical therapies. They are particularly suitable for drug delivery, wound healing, and tissue regeneration. In this review, we address chitosan-based bio-adhesives and the mechanisms associated with them. We also discuss different chitosan composite-based bio-adhesives and their biomedical applications in wound healing, drug delivery, hemostasis, and tissue regeneration. Finally, challenges and future perspectives for the clinical use of chitosan-based bio-adhesives are discussed.

Dentine hypersensitivity (DH) is often related to the exposure of dentin tubules. Mineral particles, such as hydroxyapatite and bioactive glass, can provide calcium and phosphate ions to temporarily block dentin tubules via the biomineralization process, serving as feasible alternatives for DH treatment. However, due to the acidic microenvironment caused by dietary acids, these particles are easily eroded and dissolved, making it difficult to achieve efficient dentin tubule occlusion. Given the significant stability of silica in dietary acids and its excellent ability to bond with calcium and phosphate ions to form mineralized hydroxyapatite, we proposed to develop a micron-sized monetite/amorphous silica complex (MMSi) hydrosol to effectively seal the exposed dentin tubules. In this study, we hypothesized that the MMSi hydrosol could tolerate acid erosion and concurrently provide active sites for the calcium and phosphate ions to promote biomineralization in comparison to a micron-sized monetite (MM) hydrosol. Hence, the composition and microstructure including the surface morphology, silica content and phase composition of MMSi were investigated to verify the presence of silica. The results of the ion release and in vitro biomineralization process indicated that silica did not hinder the calcium and phosphate ion release and the formation of hydroxyapatite via the biomineralization process. The acid-resistant test suggested that the MMSi hydrosol exhibited a significantly slower corrosion rate than the MM hydrosol when treated with citric acid. Notably, the silica in the MMSi hydrosol retained the ability to induce the nucleation and crystallization of hydroxyapatite during de/remineralization processes. Finally, the MMSi hydrosol was mixed with commercialized toothpaste to explore its efficacy in dentin tubule occlusion via cycling de/remineralization processes. As a result, compared to the MM hydrosol, the toothpaste containing the MMSi hydrosol presented excellent acid-resistant ability and dentin tubule occlusion outcomes, which indicated that the MMSi hydrosol could be a potential promise in the long-term treatment of DH.

Unconventional luminescent polymers have attracted considerable attention in the biological field due to their intrinsic fluorescence properties and excellent biocompatibility. However, exploring the luminescent properties of thiol-containing polymers and the mechanism of their scavenging of ROS remains unclear. In this work, we synthesised three kinds of hyperbranched polysiloxanes (HE, HP, and HB) with terminal thiol groups containing different chain lengths by the polycondensation reaction. Surprisingly, HP exhibits longer-wavelength emission at 480 nm with a quantum yield of 12.23% compared to HE and HB. Experiments and density functional theory (DFT) calculations have revealed that the rigidity of the conformation is enhanced by substantial hydrogen bonds and through-space O⋯O interactions in the polymer structure. These interactions, combined with the rigid carbon chains, balance the flexibility of the Si–O–C chain segments, which emerges as a critical factor contributing to the superior fluorescence performance of HP. In addition, HP exhibits excellent biocompatibility and ROS scavenging ability with a scavenging capacity of up to 35.095%. This work provides a new fluorescent polymer for scavenging ROS for the treatment of ROS-related diseases.

The primary objective of this study was to implement a hierarchical approach to enhance the conformational stability of a selected group of peptides by incorporating trans-(1S,2S)-2-aminocyclopentanecarboxylic acid (trans-ACPC). The influence of residue mutation on the peptide structures was investigated using circular dichroism, analytical ultracentrifugation, and vibrational spectroscopy. The resulting nanostructures were examined via transmission electron microscopy. The incorporation of trans-ACPC led to increased conformational stability and self-assembling propensity in peptides containing constrained β-amino acid residues.

Cancer is a significant global health challenge, and while chemotherapy remains a widely used treatment, its non-specific toxicity and broad distribution can lead to systemic side effects and limit its effectiveness against tumors. Therefore, the development of safer chemotherapy alternatives is crucial. Prodrugs hold great promise, as they remain inactive until they reach the cancer site, where they are selectively activated by enzymes or specific factors, thereby reducing side effects and improving targeting. However, subtle differences in the microenvironments between tumors and normal tissue may still result in unintended cytotoxicity. Bioorthogonal reactions, known for their selectivity and precision without interfering with natural biochemical processes, are gaining attention. When combined with prodrug strategies, these reactions offer the potential to create highly effective chemotherapy drugs. This review examines the safety and efficacy of prodrug strategies utilizing various bioorthogonal reactions in cancer treatment.

In recent decades, polysaccharide-based hydrogels have gained significant attention due to their natural biocompatibility, biodegradability, and non-toxicity. The potential for using polysaccharides to synthesize hydrogels is due to their ability to support cell proliferation, which is important for practical applications, particularly in the biomedical field. In this study, we have synthesized a chitosan–α-naphthal hydrogel film using a cost-effective one-step synthesis approach. The prepared hydrogel film exhibited high encapsulation efficiency for antibacterial drugs such as ciprofloxacin and lomefloxacin, with the ability to release the antibiotics in a controlled manner over an extended period and prevent long-term bacterial infections. Moreover, the Korsmeyer and Peppas power law, based on Fickian diffusion, was employed to model the entire complex drug release process and predict the drug release behavior. The hydrogel film also shows pH-induced swelling ability due to the presence of an imine bond in the hydrogel network, which is degradable at acidic pH. The incorporated therapeutic agents having antibacterial activity were effective against Gram-negative (Escherichia coli DH5α) and Gram-positive (Staphylococcus aureus subsp. aureus) bacterial strains. A wound dressing material should possess mechanical strength, but the prepared hydrogel film has low mechanical strength. To increase the mechanical strength, we have infused pineapple leaf fibers (PLFs) in the film network, resulting in a mechanical strength of 1.12 ± 0.89 MPa. In addition to its mechanical strength, significant cell viability against human embryonic kidney (HEK-293) cells was observed from in vitro cell culture experiments for this PLF-hydrogel film. As a result, the prepared therapeutic agent-loaded hydrogel film under study meets the requirements to be considered for use as a wound dressing material.

Hydrogen bond-mediated supramolecular crystalline materials, such as hydrogen-bonded organic frameworks, offer a promising strategy for protein biomineralization, yet the intricate design and multi-step synthesis of specific orthogonal units in molecular building blocks pose a significant synthetic challenge. Identifying new classes of natural building blocks capable of facilitating supramolecular framework construction while enabling stable protein binding has remained an elusive goal. Here, we introduce a versatile assembly strategy enabling the organization of diverse proteins and phenolic building blocks into highly crystalline hydrogen-bonded supramolecular phenolic frameworks (ProteinX@SPF). The natural ellagic acid (EA) exhibits a centrosymmetric structure with catechol groups on each molecular side, facilitating hydrogen bonding with protein amino acid residues for primary nucleation. Subsequently, EA self-assembles into ProteinX@SPF through hydrogen bonding and π–π interactions. The multiple hydrogen-bonding interactions impart structural rigidity and directional integrity, conferring ProteinX@SPF biohybrids with remarkable resistance to harsh conditions while preserving protein bioactivity. Additionally, the supramolecular stacking induced by π–π interactions endows ProteinX@SPF with long-range ordered nanochannels, which can serve as the gating to sieve the catalytic substrate and thus enhance the biocatalytic specificity. This work sheds light on biomineralization with natural building blocks for functional biohybrids, showing enormous potential in biocatalysis, sensing, and nanomedicine.

Pyrene–urea derivatives and acetate anions were used to investigate the excited-state intermolecular proton transfer (ESPT) reaction, where a molecule undergoes intermolecular proton transfer to form a tautomer species in the excited state. Since ESPT occurs when intermolecular hydrogen bonds exist between urea compounds and acetate species, we hypothesize that this reaction might be influenced by compounds with hydroxy groups. In this study, cyclodextrins, saccharides, and ethanol were examined to assess the effects of hydroxy groups on the ESPT reaction. After introducing various hydroxy compounds into the urea–acetate system in dimethylformamide, we observed differences in the fluorescence spectra and fluorescence decay curves. These differences indicate varying interactions between the hydroxy compounds and complexes, leading to distinct fluorescence lifetime behaviors, which makes fluorescence lifetime imaging technology particularly suitable.