Real-time visualization of morphology-dependent self-motion of hyaluronic acid nanomaterials in water

Cyclodextrin-based supramolecular nanogels decorated with mannose for short peptide encapsulation

Nanogels are aqueous dispersions of hydrogel particles formed by physically or chemically cross-linked polymer networks of nanoscale size. Herein, we devised a straightforward technique to fabricate a novel class of physically cross-linked nanogels via a self-assembly process in water involving α-cyclodextrin and a mannose molecule that was hydrophobically modified using an alkyl chain. The alkyl chain-modified mannose was synthesized in five steps, starting with D-mannose. Subsequently, nanogels were formed by subjecting α-cyclodextrin and the hydrophobically modified mannose to magnetic stirring in water. By adjusting the mole ratio between the hydrophobically modified mannose and α-cyclodextrin, nanogels with an average 100-150 nm diameter were obtained. Physicochemical and structural analyses by 1H NMR and X-ray diffraction unveiled a supramolecular and hierarchical mechanism underlying the creation of these nanogels. The proposed mechanism of nanogel formation involves two distinct steps: initial interaction of hydrophobically modified mannose with α-cyclodextrin resulting in the formation of inclusion complexes, followed by supramolecular interactions among these complexes, ultimately leading to nanogel formation after 72 h of stirring. We demonstrated the nanogels' ability to encapsulate a short peptide ([p-tBuF2, R5]SHf) as a water-soluble drug model. This discovery holds promise for potentially utilizing these nanogels in drug delivery applications.

Experimental and Molecular Docking Studies on Enzyme-Driven Biohybrid-Inspired Micromotors Based on Amylose-b-(PEG-co-PBA) Inclusion Complexes

Amylose is a linear polysaccharide with a unique ability to form helical inclusion complexes with the appropriate guest components. Numerous studies have been conducted on encapsulation of bioactive compounds for various applications. In the biomedical field, biohybrid micro/nanomotors (MNMs) have emerged as innovative candidates due to their excellent biocompatible and biodegradable properties. This study was inspired by the biohybrid- and enzymatic-propelled MNMs and explored the potential of amylose inclusion complexes (ICs) in creating these MNMs. The study developed a new type of micromotor made from (PEG-co-PBA)-b-amylose. Nanoprecipitation, dimethyl sulfoxide (DMSO), and ultrasound-treated methods were employed to create spherical, thick crystalline, and rod-bacterial-like morphologies, respectively. Candida antarctica lipase B (CALB) was used as the catalytic fuel to induce the motion by the enzymatic degradation of ester linkages in the polymeric segment. Optical microscopy was utilized to observe the motion of the motors following incubation with enzyme concentrations of 5, 10, and 20% (w/w). The results demonstrated that the velocity of the motors increased proportionally with the percentage of added enzyme. Additionally, a comprehensive molecular docking evaluation with PyRx software provided insight into the interaction of the CALB enzyme with polymeric moieties and demonstrated a good affinity between the enzyme and polymer in the binding site. This study provides novel insight into the design and development of enzymatically driven polymeric micromotors and nanomotors.

Hyaluronan nanoplatelets exert an intrinsic anti-inflammatory activity in a rat model of bladder painful syndrome/interstitial cystitis

Glycosaminoglycan (GAG) replenishment therapy consists of the instillation of GAG solutions directly in the bladder to alleviate Bladder Painful Syndrome/Interstitial Cystitis (BPS/IC). However, several issues were reported with this strategy because the GAG solutions are rapidly eliminated from the bladder by spontaneous voiding, and GAG have low bioadhesive behaviors. Herein, GAG nanomaterials with typical flattened morphology were obtained by a self-assembly process. The formation mechanism of those nanomaterials, denoted as nanoplatelets, involves the interaction of α-cyclodextrin cavity and alkyl chains covalently grafted on the GAG. Three GAG were used in this investigation, hyaluronan (HA), chondroitin sulfate (CS), and heparin (HEP). HA NP showed the best anti-inflammatory activity in an LPS-induced in vitro inflammation model of macrophages. They also exhibited the best therapeutic efficacy in a BPS/IC rat inflammation model. Histological examinations of the bladders revealed that HA NP significantly reduced bladder inflammation and regenerated the bladder mucosa. This investigation could open new perspectives to alleviate BPS/IC through GAG replenishment therapy.