Peptide nanosponges designed for rapid uptake by leukocytes and neural stem cells

β-Cyclodextrin-crosslinked synthetic neuropeptide Y-based nanosponges in epilepsy by contributing GABAergic signal

Neuropeptide Y (NPY) is a polypeptide sequence useful in regulating physiological functions like homeostasis, feeding, etc., but its usage is restricted due to its short half-life. β-cyclodextrin-crosslinked nanosponges improve the drug release and stability due to its wide cavity, which is helpful to deliver therapeutics. The present work aimed to formulate synthetic NPY-based nanocarriers as sponges by polymer condensation mechanism using design experiment to improve the peptide release and stability. The validated nanosponges exhibited a particle size of 423.42 ± 5.32 nm, 75.82 ± 7.43 % entrapment efficiency and 83.50 ± 6.54 % NPY release for 24 h. The NPY and β-cyclodextrin interaction was confirmed by X-ray diffraction, Fourier transform infrared and nuclear magnetic resonance spectroscopy. The NPY-loaded nanosponges were found stable for 6 months at two conditions (5 ± 2 °C and 25 ± 2 °C). The cross-linked nanocarriers of synthetic peptide-based nanosponges powder at different doses were administered intranasally using a metered-dose inhaler in the animal model to check its antiepileptic activity. The synthetic NPY-loaded nanosponges at higher doses showed significant antiepileptic effects equivalent to the standard drug (administered orally) in maximal electroshock and chemically-induced seizures with an increase of NPY in the brain directly proportional to GABAergic signalling by increase in GABA levels resulting in convulsions attenuation.

Sponge particulates for biomedical applications: Biofunctionalization, multi-drug shielding, and theranostic applications

Sponge particulates have attracted enormous attention in biomedical applications for superior properties, including large porosity, elastic deformation, capillary action, and three-dimensional (3D) reaction environment. Especially, the tiny porous structures make sponge particulates a promising platform for drug delivery, tissue engineering, anti-infection, and wound healing by providing abundant reservoirs of broad surface and internal network for cargo shielding and shuttling. To control the sponge-like morphology and improve the diversity of drug loading, some optimized preparation techniques of sponge particulates have been developed, contributing to the simplified preparation process and improved production reproducibility. Bio-functionalized strategies, including target modification, cell membrane camouflage, and hydrogel of sponge particulates have been applied to modulate the properties, improve the performance, and extend the applications. In this review, we highlight the unique physical properties and functions, current manufacturing techniques, and an overview of spongy particulates in biomedical applications, especially in inhibition of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity. Moreover, the current challenges and prospects of sponge particulates are discussed rationally, providing an insight into developing vibrant fields of sponge particulates-based biomedicine.

Self-assembly of trigonal building blocks into nanostructures: molecular design and biomedical applications

Trigonal molecules have a special triskelion structure similar to clathrin protein, providing great inspiration for constructing artificial nanoassemblies. To date, various synthetic trigonal conjugates have been designed for supramolecular self-assembly, which have demonstrated versatile and controllable self-assembly ability in materials science. Here we will review the design of trigonal (sometimes called three-legged, tripodal, C3-symmetric, or triskelion) building blocks that can self-assemble into various nanostructures and discuss the biomedical applications of the self-assembled nanomaterials.

Nano-Inspired Technologies for Peptide Delivery

Nano-inspired technologies offer unique opportunities to treat numerous diseases by using therapeutic peptides. Therapeutic peptides have attractive pharmacological profiles and can be manufactured at relatively low costs. The major advantages of using a nanodelivery approach comprises significantly lower required dosages compared to systemic delivery, and thus reduced toxicity and immunogenicity. The combination of therapeutic peptides with delivery peptides and nanoparticles or small molecule drugs offers systemic treatment approaches, instead of aiming for single biological targets or pathways. This review article discusses exemplary state-of-the-art nanosized delivery systems for therapeutic peptides and antibodies, as well as their biochemical and biophysical foundations and emphasizes still remaining challenges. The competition between using different nanoplatforms, such as liposome-, hydrogel-, polymer-, silica nanosphere-, or nanosponge-based delivery systems is still "on" and no clear frontrunner has emerged to date.