Mechanistic crosstalk of extracellular calcium-mediated regulation of maturation and plasticity in human monocytes

Luminescent ultrashort peptide hydrogelator with enhanced photophysical implications and biocompatibility

Luminescent peptide hydrogelators have garnered significant attention in biomedical sciences and materials chemistry due to their biological relevance and tunable photophysical features. In this work, we have designed and synthesized a novel ultrashort peptide hydrogelator comprising a tripeptide sequence (FFE) integrated with 1,8-naphthalimide (NI) as an aggregation-induced emissive unit having rich and tuneable photophysical properties. The hydrogelator could self-assemble and form a self-supporting hydrogel having a highly ordered intertwined network structure at pH 5.5 with a minimum gelation concentration of 1 wt/v%. Interestingly, due to the presence of the emissive unit, the assembly could demonstrate strong blue luminescence, which has been thoroughly investigated experimentally. Moreover, spectroscopic investigations and molecular dynamics simulation studies suggest the formation of a β-sheet structure through extended intermolecular H-bonding interactions within the peptide backbones and the strong π-π-stacking interaction among aromatic units, which drive the self-assembly and hydrogelation. The emissive unit of the peptide could arrange in a J-type aggregation pattern and adopt right-handed helical induced chirality in the assembled state. Additionally, the system could exhibit a high safety profile and excellent biocompatibility, when tested in a series of cell lines in vitro. Finally, the intracellular uptake of the system has been exploited, showcasing its luminescence characteristics for potential applications in cellular imaging. The luminescent system holds significant promise for advancing cellular imaging techniques, offering new avenues for research in the future. Briefly, this work highlights the importance of luminescent ultrashort peptide hydrogelators for developing next-generation low-cost functional biomaterials.

Rebamipide nanocrystal with improved physicomechanical properties and its assessment through bio-mimicking 3D intestinal permeability model

This study investigated the formulation and characterization of rebamipide nanocrystals (REB-NCs) to enhance the solubility and permeability of rebamipide, an anti-ulcer medication known for its low aqueous solubility and permeability, classified as BCS class IV. Employing high-pressure homogenization and wet milling techniques, we successfully achieved nanonization of rebamipide, resulting in stable nanosuspensions that were subsequently freeze-dried to produce REB-NCs with an average particle size of 223 nm. Comprehensive characterization techniques, including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) confirmed the crystalline nature of the nanocrystals and their compatibility with the selected excipients. The saturation solubility study revealed a remarkable three-fold enhancement in PBS pH 7.4 compared to rebamipide API, indicating the effectiveness of the nanocrystal formulation in improving drug solubility. Furthermore, 3D in-vitro permeability assessments conducted on Caco-2 cell monolayers demonstrated an noticeable increase in the permeability of REB-NCs relative to the pure active pharmaceutical ingredient (API), highlighting the promise of this formulation to enhance drug absorption. The dissolution profile of the nanocrystal tablets exhibited immediate release characteristics, significantly outperforming conventional formulations in terms of the dissolution rate. This research underscores the potential of nanomilling as a scalable, environment-friendly, and less toxic approach to significantly enhance the bioavailability of rebamipide. By addressing the challenges associated with the solubility and permeability of poorly water-soluble drugs, our outcome offers insightful information into developing efficient nanomedicine strategies for enhancing therapeutic outcomes.

A 3D in-vitro biomimicking Caco-2 intestinal permeability model-based assessment of physically modified telmisartan towards an alkalizer-free formulation development

Efficient telmisartan delivery for hypertension management requires the incorporation of meglumine and/or sodium hydroxide as an alkalizer in the formulation. Long-term use of powerful alkalis with formulation as part of chronic therapy can cause metabolic alkalosis, ulcers, diarrhea, and body pain. Here, we aimed to design a telmisartan formulation without alkalizers. Telmisartan properties were tailor-made by microfluidizer-based physical modification. After microfluidization, telmisartan nanosuspension was lyophilized to obtain telmisartan premix powder. The optimized telmisartan nanosuspension had an average particle size of 579.85 ± 32.14 nm. The lyophilized premix was characterized by FT-IR, DSC, and PXRD analysis to ensure its physicochemical characteristics. The solubility analysis of premix showed 2.2 times, 2.3 times, and 6 times solubility improvement in 0.1 N HCl, phosphate buffer pH 7.5, and pH 6.8 compared to pure telmisartan. A 3D in-vitro Caco-2 model was developed to compare apparent permeability of API and powder premix. It showed that the powder premix was more permeable than pure API. The tablet formulation prepared from the telmisartan premix showed a dissolution profile comparable to that of the marketed formulation. The technique present herein can be used as a platform technology for solubility and permeability improvement of similar classes of molecules.

Macrophages in guided bone regeneration: potential roles and future directions

Guided bone regeneration (GBR) is one of the most widely used and thoroughly documented alveolar bone augmentation surgeries. However, implanting GBR membranes inevitably triggers an immune response, which can lead to inflammation and failure of bone augmentation. It has been shown that GBR membranes may significantly improve in vivo outcomes as potent immunomodulators, rather than solely serving as traditional barriers. Macrophages play crucial roles in immune responses and participate in the entire process of bone injury repair. The significant diversity and high plasticity of macrophages complicate our understanding of the immunomodulatory mechanisms underlying GBR. This review provides a comprehensive summary of recent findings on the potential role of macrophages in GBR for bone defects in situ. Specifically, macrophages can promote osteogenesis or fibrous tissue formation in bone defects and degradation or fibrous encapsulation of membranes. Moreover, GBR membranes can influence the recruitment and polarization of macrophages. Therefore, immunomodulating GBR membranes are primarily developed by improving macrophage recruitment and aggregation as well as regulating macrophage polarization. However, certain challenges remain to be addressed in the future. For example, developing more rational and sophisticated sequential delivery systems for macrophage activation reagents; addressing the interference of bone graft materials and dental implants; and understanding the correlations among membrane degradation, macrophage responses, and bone regeneration.

Covalent Conjugation of Small Molecule Inhibitors and Growth Factors to a Silk Fibroin-Derived Bioink to Develop Phenotypically Stable 3D Bioprinted Cartilage

Implantation of a phenotypically stable cartilage graft could represent a viable approach for repairing osteoarthritic (OA) cartilage lesions. In the present study, we investigated the effects of modulating the bone morphogenetic protein (BMP), transforming growth factor beta (TGFβ), and interleukin-1 (IL-1) signaling cascades in human bone marrow stromal cell (hBMSC)-encapsulated silk fibroin gelatin (SF-G) bioink. The selected small molecules LDN193189, TGFβ3, and IL1 receptor antagonist (IL1Ra) are covalently conjugated to SF-G biomaterial to ensure sustained release, increased bioavailability, and printability, confirmed by ATR-FTIR, release kinetics, and rheological analyses. The 3D bioprinted constructs with chondrogenically differentiated hBMSCs were incubated in an OA-inducing medium for 14 days and assessed through a detailed qPCR, immunofluorescence, and biochemical analyses. Despite substantial heterogeneity in the observations among the donors, the IL1Ra molecule illustrated the maximum efficiency in enhancing the expression of articular cartilage components, reducing the expression of hypertrophic markers (re-validated by the GeneMANIA tool), as well as reducing the production of inflammatory molecules by the hBMSCs. Therefore, this study demonstrated a novel strategy to develop a chemically decorated, printable and biomimetic SF-G bioink to produce hyaline cartilage grafts resistant to acquiring OA traits that can be used for the treatment of degenerated cartilage lesions.