Macromolecular bioscience最新文献

This study investigates the size-dependent mechanical properties of electrospun polycaprolactone (PCL) nanofibers by analyzing the relationship between fiber diameter and Young's modulus. Experimental data reveal a clear inverse trend: as fiber diameter decreases, stiffness increases significantly, indicating strong surface and confinement effects at the nanoscale. Two theoretical models were employed to interpret the observed behavior: a simplified core–shell model (Model 1) and an extended model (Model 2) incorporating surface tension and curvature elasticity. Both models accurately fit the experimental data across a diameter range of 450–850 nm, with Model 2 providing slightly better agreement at intermediate diameters (∼600–750 nm), where surface mechanics become more prominent. The enhanced stiffness in thinner fibers is attributed to increased surface-to-volume ratio and tighter molecular packing, while larger fibers exhibit bulk-dominated mechanical responses. These findings highlight the importance of nanoscale geometry and surface effects in determining mechanical properties and suggest that fiber stiffness can be systematically tuned via diameter control during electrospinning.

T cells in the lymph nodes play an important role in cancer immunotherapy. Dendrigraft polylysines (DGLs) are potent nanoplatforms used in nanomedicine. In the present study, DGLs were modified with 1,2-cyclohexanedicarboxylic acid (CHex) and phenylalanine (Phe) to produce DGL-CHex-Phe for drug delivery into T cells. Various DGL-CHex-Phe polymers were synthesized using different generations of DGL by reacting with Phe at different ratios. DGL-CHex-Phe polymers with a higher generation and more Phe efficiently associated with Jurkat cells, a T cell model. These polymers are internalized by T cells via an amino acid transporter and/or direct membrane association. The hydrophobic model drug, paclitaxel (PTX), was loaded onto the polymers. DGL(G3)-CHex-Phe93 loaded the most PTX molecules among them, and most of them were retained therein for 3 h. PTX-loaded polymers exhibited cytotoxic effects against Jurkat cells at a level similar to that of free PTX. DGL(G3)-CHex-Phe93 efficiently accumulated in lymph nodes after intradermal injection, which was partially co-localized with T cells. These results suggested that DGL(G3)-CHex-Phe93 is useful for the delivery of hydrophobic drugs into immune cells including T cells in lymph nodes.

Augmentation cystoplasty has different side effects in urinary bladder reconstruction. Accordingly, it is necessary to develop substitutes using natural and synthetic biomaterials to address current problems. This study evaluates the potential of a triple-layered composite scaffold for bladder regeneration. The triple-layered scaffold consists of a silk fibroin (SF) film blended with polyethylene oxide (PEO), a decellularized human amniotic membrane (DHAM), and a lyophilized SF sponge, which is seeded with adipose tissue-derived stem cells (ADSCs) encapsulated in collagen hydrogel. The mechanical properties of the triple-layered scaffolds closely resemble those of human bladder tissue. The cell survival, proliferation, and viability of the different layers of the scaffold are assessed. The results show that DHAM and silk sponge at a concentration of 4% wt v⁻¹ achieve a high level of biocompatibility. To study potential stone formation, scaffolds either with DHAM or without DHAM are exposed to human urine. Field emission scanning electron microscopy (FESEM) and X-ray diffraction analyses indicate that the scaffolds with DHAM do not exhibit any signs of erosion or the creation of crystalline particles after 7 days. In conclusion, the data presented in this study highlight a new triple-layered scaffold for the purpose of bladder tissue engineering.

As an emerging technology, biofabrication combines biopolymers and living cells to create functional tissues, allowing the development of structures that closely mimic native tissues. The use of fiber-reinforced materials is of particular interest, as it enhances both mechanical properties and cellular behavior. Incorporating fiber fragments into bio-inks not only strengthens printed structures but also supports cell survival by lowering polymer concentrations and thus the stress exerted on the cells during printing. A key factor in optimizing fiber-reinforced bio-inks is the controlled fiber shortening, comprising cutting or breaking, which improves printability and mechanical integrity of printed constructs. However, current methods for fiber fragmentation face significant limitations, including material-specific dependencies, scalability challenges, and requirements of specialized equipment, which may not be accessible in all laboratories. To overcome these challenges, we introduce a novel approach utilizing ultraviolet irradiation to achieve controlled fiber fragmentation. The average fiber length resulting from specific irradiation times can be estimated using a multi-modal Weibull analysis. This technique is validated on fibers made of polycaprolactone (PCL) and gelatin blends, demonstrating its cost-effectiveness, biocompatibility, and simplicity. This study provides a practical solution for fiber fragment production and average length estimation, offering an accessible and scalable alternative for fiber-based biofabrication applications.

This study utilizes cellulose sourced from cotton linters to synthesize cellulose esters—hexanoate, benzoate, and mixed hexanoate-benzoate—with varying degrees of substitution (DS). These esters create electrospun mats that immobilize Pseudomonas fluorescens lipase (PFL), also in a configuration where an intermediate layer is added to a mat using an airbrush filled with PFL, covered by a third layer of electrospun mat. PFL-incorporated spheres are produced from cellulose ester solutions. DS, acyl chain length, and electrospinning parameters influence the morphology of the electrospun mat, which consists of nanofibers and ultrafine fibers. The PFL-incorporated mats show poor catalytic activity in resolving racemic (R,S)-2-chloro-1-phenylethanol, likely due to enzyme deactivation from high-voltage electrospinning. In contrast, mat-layered structures with PFL immobilized without voltage nearly doubled the conversion rate, although it was still lower than that of free enzymes. Spheres enhanced biocatalysis, achieving a 40% conversion rate with 94% enantiomeric purity while retaining 76% of their initial conversion rate in a subsequent reaction cycle. This research is the first to explore cellulose esters for the enzymatic immobilization of PFL to resolve a racemic mixture. The findings may enable PFL-incorporated structures in broader biocatalysis applications; the materials created may be tested to support the immobilization of other enzymes.