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The design and development of a bio-adhesive hydrogel with on-demand removability and excellent antibacterial activities are meaningful to achieve high wound closure effectiveness and post-wound-closure care, which is desirable in clinical applications. In this work, a series of adhesive antioxidant antibacterial hydrogels containing peptides from Periplaneta americana (PAP) were prepared through multi-dynamic-bond cross-linking among 3,4-dihydroxybenzaldehyde (DBA) containing catechol and aldehyde groups and chitosan grafted with 3-carboxy-4-fluorophenylboronic acid (CS-FPBA) to enable the effective adhesion of skin tissues and prevention of bacterial infection of wound. PAP was derived from alcohol-extracted residues generated during the pharmaceutical process, aiming to minimize resource wastage and achieve the high-value development of such a medicinal insect. The hydrogel was prepared by freezing-thawing with no toxic crosslinkers. The multi-dynamic-bond cross-linking of dynamic borate ester bonds and dynamic Schiff base bonds can achieve reversible breakage and re-formation and the adhesive strength of CS-FPBA-DBA-P-gel treated with a 20 % glucose solution dramatically decreased from 3.79 kPa to 0.35 kPa within 10 s. Additionally, the newly developed hydrogel presents ideal biocompatibility, hemostasis and antibacterial activity against Staphylococcus aureus and Escherichia coli compared to commercial chitosan gel (approximately 50 % higher inhibition rate), demonstrating its great potential in dealing with infected full-thickness skin wounds., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Carriers play an important role in improving the aerosolization performance of dry powder inhalers (DPIs). Despite that intensive attention had been paid to the establishment of the advanced carriers with controllable physicochemical properties in recent years, the design and optimization of carrier-based DPIs remain an empiricism-based process. DPIs are a powder system of complex multiphase, and thus their physicochemical properties cannot fully explain the powder behavior. A comprehensive exposition of powder properties is demanded to build a bridge between the physicochemical properties of carriers and the aerosolization performance of DPIs. In this study, an FT-4 powder rheometer was employed to explore the powder properties, including dynamic flow energy, aeration, and permeability of the chitosan-mannitol binary carriers (CMBCs). CMBCs were self-designed as an advanced carrier with controllable surface roughness to obtain enhanced aerosolization performance. The specific mechanism of CMBCs to enhance the aerosolization performance of DPIs was elaborated based on the theory of pulmonary delivery processes by introducing powder properties. The results exhibited that CMBCs with appropriate surface roughness had lower special energy, lower aeration energy, and higher permeability. It could be predicted that CMBC-based DPIs had greater tendency to fluidize and disperse in airflow, and the lower adhesion force between particles enabled drugs to be detached from the carrier to achieve higher fine particle fractions. The specific mechanism on how physicochemical properties influenced the aerosolization performance during the pulmonary delivery processes could be figured out with the introduction of powder properties., (© 2022. The Author(s), under exclusive licence to American Association of Pharmaceutical Scientists.)

Dissolving microneedles (DMN) have been studied as a drug delivery system to enhance the transport of drug molecules across the skin with almost no pain. However, the poor dissolving ability of microneedles in the skin and low drug loading have limited their potential application. The aim of this study was to develop a novel dissolving microneedle system with improved dissolving ability for the delivery of poorly water soluble contraception drug, levonorgestrel (LNG). Chitosan and beta-sodium glycerophosphate (β-GP) were incorporated in the formulation of microneedles. It was found that 69.32 ± 4.23% of the microneedles penetrated through the skin and dissolved within the first 2 h, which was almost 2-fold higher than that of the conventional microneedles. In addition, drug loading was significantly increased by packaging LNG into the molecules of hydroxypropyl beta cyclodextrin (HP-β-CD) to form LNG-HP-β-CD inclusion compounds. The use of chitosan and β-GP together with HP-β-CD inclusion compounds was shown to enhance the bioavailability of LNG transdermally. This novel DMN system resulted in a similar pharmacokinetic profile as that following oral administration. In addition to similar C max and AUC values, drug concentrations in the blood were more consistent following the DMN in comparison to oral administration. [ABSTRACT FROM AUTHOR]