A parallel approach to the discovery of carrier delivery vehicles to enhance antigen immunogenicity

Peptide-Based Hydrogels: New Materials for Biosensing and Biomedical Applications

Peptide-based hydrogels have attracted increasing attention for biological applications and diagnostic research due to their impressive features including biocompatibility and biodegradability, injectability, mechanical stability, high water absorption capacity, and tissue-like elasticity. The aim of this review will be to present an updated report on the advancement of peptide-based hydrogels research activity in recent years in the field of anticancer drug delivery, antimicrobial and wound healing materials, 3D bioprinting and tissue engineering, and vaccines. Additionally, the biosensing applications of this key group of hydrogels will be discussed mainly focusing the attention on cancer detection.

Entrapment of horseradish peroxidase into nanometer-scale metal-organic frameworks: a new nanocarrier for signal amplification in enzyme-linked immunosorbent assay

Horseradish peroxidase (HRP) was highly loaded into large holes of nanometer-scale metal-organic frameworks (i.e., PCN-333(Al)) for signal amplification in enzyme-linked immunosorbent assay (ELISA). The enzyme-labeled antibody complex prepared using nanometer-scale PCN-333(Al) maintained a high catalytic efficiency. Its V_m and K_cat values with 3,3',5,5'-Tetramethylbenzidine (TMB)-H₂O₂ as substrates were 4.84 × 10^-5 mM/s and 4.84 × 10⁴ min^-1, respectively. We demonstrated an HRP@PCN-333 signal amplification strategy for colorimetric assay of human prostate-specific antigen (PSA). The linear range of PSA detection by using this method was 15-165 pg/mL, and the limit of detection was 6 pg/mL (S/N = 3), indicating the potential application of this method in detecting disease markers under clinical conditions. The presented strategy exhibited the characteristics of significantly increased amount of labeled enzymes, improved stability and utilization of enzymes, simple preparation process of enzyme-labeled antibodies, and low cost.

Recent advances of self-assembling peptide-based hydrogels for biomedical applications

Peptide-based hydrogels have been proven to be preeminent biomedical materials due to their high water content, tunable mechanical stability, great biocompatibility and excellent injectability. The ability of peptide-based hydrogels to provide extracellular matrix-mimicking environments opens up opportunities for their biomedical applications in fields such as drug delivery, tissue engineering, and wound healing. In this review, we first describe several methods commonly used for the fabrication of robust peptide-based hydrogels, including spontaneous hydrogelation, enzyme-controlled hydrogelation and cross-linking-enhanced hydrogelation. We then introduce some representative studies on their applications in drug delivery and antitumor therapy, antimicrobial and wound healing materials, and 3D bioprinting and tissue engineering. We hope that this review facilitates the advances of hydrogels in biomedical applications.

Polymer-Protein Core-Shell Nanoparticles for Enhanced Antigen Immunogenicity

Nanoengineered vaccine platforms can be modeled after viruses and other pathogens with highly organized and repetitive structures that trigger the host immune system. Here we demonstrated a pyridine-grafted poly(ε-caprolactone)-based polymer-protein core-shell nanoparticles (PPCS-NPs) platform can effectively trigger the host immune system and lead to significantly higher antibody titers.

Biologically templated organic polymers with nanoscale order

Methods for the construction of ordered nanoscale arrays have been implicated in fields ranging from separation technologies to microelectronics. Yet, despite the plethora of nanoscale structures assembled in nature that use a templating strategy, chemists have been unable to replicate this success. A technology is reported for templated organic polymers composed of filamentous bacteriophage-polyacrylamide biomacromolecules that self-assemble into highly ordered helical bundles displaying hexagonal close packing. The results align with a previously reported mathematical prediction for the close packing of flexible tubes. This biopolymeric assembly can be viewed as a magnification of the inherent microscopic chirality and helicity present in individual phage particles at the macroscale level.

Solid-phase synthesis and kinetic characterization of fluorogenic enzyme-degradable hydrogel cross-linkers

Of critical importance in drug delivery and tissue engineering applications is the degradability of implanted polymeric materials. The use of peptide-derived cross-linkers in hydrogel design is a valuable approach by which polymeric carriers can be endowed with enzymatic degradability in a predictable, "programmable" fashion. The solid-phase synthesis strategy described herein allows for an expeditious, flexible synthesis of bis-acrylamide-derivatized peptides with complex modifications, as exemplified by the incorporation of fluorophore and quencher moieties into a matrix metalloprotease (MMP)-degradable cross-linker. The crude synthetic product was obtained in high yield and purity and purified by standard methods; it was then used directly for polymerization without the need for tedious and often nonchemoselective solution-phase modifications. Functional appendages incorporated for detection provided a direct, quantitative link between enzymatic activity and hydrogel degradation using routine methods for identification of optimal enzyme-specific degradability.