Biopolymers最新文献

Ethanol dehydration is a common step in both scaffold manufacturing and tissue processing, yet the influence of ethanol on collagen is not well understood. This study examined the effects of dehydration, via ethanol treatment and air drying, on collagen structure, behavior, mechanics, and rehydration capacity. Multiple material characterization methods were used including Fourier Transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy, thermogravimetric analysis, small/medium angle x-ray scattering, volumetric swelling analysis, and tensile testing. Ethanol dehydration removed bulk water from scaffolds, making them stronger and stiffer, but also showed loss of molecular water. This molecular water appears to act as a collagen stabilizer, resulting in less thermally stable scaffolds. The loss of molecular water is also evident in the molecular d-spacing. Secondary structure of scaffolds was also altered by ethanol, resulting in significantly enhanced rehydration capacity. Bulk water, both before and after rehydration, largely determined mechanical properties, which did not correlate with other structural measures such as FTIR. While rehydration largely returned collagen spacing to pre-ethanol treated state, structural alterations seen in FTIR cannot be recovered. These results have implications for not only collagen scaffolds, but in many tissue engineering and processing applications.

This review explores the multifaceted role of nanocellulose, comprising cellulose nanofibers (CNFs), cellulose nanocrystals (CNCs), and bacterial nanocellulose (BNC), in the design and fabrication of scaffolds for biomedical applications. Structural insights into nanocellulose reveal its capacity to mimic the extracellular matrix (ECM), providing a conducive environment for cell adhesion, proliferation, and differentiation. Modification strategies such as surface functionalization, grafting with bioactive molecules, and incorporation of therapeutic agents further enhance its biological performance and targeted functionality. Innovative scaffold fabrication techniques, including 3D printing, electrospinning, freeze-drying, gas foaming, and cell sheet engineering, are discussed in the context of tailoring scaffold architecture to meet the mechanical and biological requirements of various tissues. The integration of nanocellulose into composite materials and its synergy with other polymers and biomolecules demonstrate great potential in addressing complex tissue regeneration challenges. Biomedical applications cover a wide range of tissues, including skin, bone, cartilage, muscle, nerve, and vascular systems, highlighting the versatility of nanocellulose-based scaffolds. Nanocellulose stands as a key biomaterial in the development of next-generation, eco-friendly scaffolds that align with the principles of sustainability and regenerative medicine.

Sulfated polysaccharides from the red microalgae Porphyridium cruentum demonstrate unique physicochemical properties and antiviral activity. Despite growing interest, it is yet unclear how the sulfates within these polysaccharides affect their rheological properties and whether they are required for the antiviral activity. We report a nondestructive method to deplete sulfates from these polysaccharides by directly exposing the growth medium to a moderate electric field (3.43 V/cm); a 5 min exposure yielded a polysaccharide fraction around the cathode, which we collected and compared to polysaccharides extracted via a traditional, ethanol-based method. Although the electric field did not affect the sugar composition of the polysaccharide and retained its gel-like properties, it substantially reduced its sulfate content (from 5.8% to 1.2%), viscosity (by fivefold), and stiffness (by eightfold) relative to the ethanol-separated fraction. Yet, the bioactivity of the sulfate-depleted polysaccharide against Herpes simplex virus 1 was only slightly reduced (~15%), suggesting that the sulfate groups do not significantly contribute to the antiviral potency of this polysaccharide. The reported electric-field separation methods is, therefore, a simple, straightforward, and nontoxic means for the direct recovery of desulfated polysaccharides from P. cruentum cultures, yielding a low-toxicity and highly stable gel-like material with enhanced amenability for antiviral applications.

Polymeric zein nanoparticles (ZNP), derived from corn protein, are biodegradable drug carriers with high stability and low synthesis costs. Their amphiphilic nature allows efficient encapsulation of both hydrophilic and lipophilic drugs, making them promising for drug delivery. However, their instability under physiological pH can limit therapeutic efficacy, necessitating protective coatings for improved absorption. This review discusses synthesis methods, coating materials, and biological activities of bioactive-coated ZNP. We found that the antisolvent method is the most commonly used due to its simplicity and cost-effectiveness, while chitosan is the preferred coating material. ZNP exhibit antioxidant, anticancer, anesthetic, antidiabetic, hypoglycemic, and immunogenic properties, as demonstrated in both in vitro and in vivo studies. Their ability to enhance bioavailability, reduce toxicity, and enable targeted drug delivery highlights their potential in nanomedicine.

Elastin-like peptides (ELPs) comprise repetitive pentapeptide sequences and exhibit liquid–liquid phase separation through lower critical solution temperature-type behavior. Their stimuli-responsive behavior has enabled diverse applications in biomedical and chemical contexts. Although the miscibility and interactions of ELP mixtures have been previously studied, it remains unclear whether mixtures of short-chain ELPs with minimal differences in intrinsic parameters, such as chain length, can exhibit distinct phase behaviors. In this study, we investigated whether synthetic short-chain ELPs differing in length by only one or two repeat units (i.e., 5 or 10 residues) could exhibit independent phase transitions in mixed systems. Turbidity measurements of single- and two-component ELP solutions supported by UPLC-MS analysis revealed stepwise phase transitions upon heating. Our mechanistic analyses revealed that the mixtures undergo a structural transition from polyproline type II helix to β-sheet or β-turn structures. In addition, although the mixtures exhibited stepwise phase separation, our results indicate that heterotypic interactions influenced the sequential phase behavior. These findings reveal that even subtle variations in the ELP chain length and architecture can drive distinct phase separation, providing a rational strategy for designing functional, multicomponent, responsive peptide-based materials.

B. Redko, E. Ragozin, B. Andrii, T. Helena, A. Amnon, S. Z., Talia, O.-H. Mor, K. Genady, and G. Gary, “Synthesis, Drug Release, and Biological Evaluation of New Anticancer Drug–Bioconjugates Containing Somatostatin Backbone Cyclic Analog as a Targeting Moiety,” Biopolymers 104 (2015): 743–752. https://doi.org/10.1002/bip.22694.

The first name of the third listed author was spelled incorrectly in the published article. It was originally published as “Andreii”, but the correct spelling is “Andrii”. The online version of this article has been corrected accordingly.

We apologize for this error.