Inflammation processes are associated with significant decreases in tissue or lysosomal pH from 7.4 to 4, a fact that argues for the application of pH-responsive drug delivery systems. However, for their design and optimization a full understanding of the release mechanism is crucial. In this study we investigated the pH-depending drug release mechanism and the influence of silk fibroin (SF) concentration and SF degradation degree of human serum albumin (HSA)-SF nanocapsules. Sonochemically produced nanocapsules were investigated regarding particle size, colloidal stability, protein encapsulation, thermal stability and drug loading properties. Particles of the monodisperse phase showed average hydrodynamic radii between 438 and 888 nm as measured by DLS and AFM and a zeta potential of -11.12 ± 3.27 mV. Together with DSC results this indicated the successful production of stable nanocapsules. ATR-FTIR analysis demonstrated that SF had a positive effect on particle formation and stability due to induced beta-sheet formation and enhanced crosslinking. The pH-responsive release was found to depend on the SF concentration. In in-vitro release studies, HSA-SF nanocapsules composed of 50% SF showed an increased pH-responsive release for all tested model substances (Rhodamine B, Crystal Violet and Evans Blue) and methotrexate at the lowered pH of 4.5 to pH 5.4, while HSA capsules without SF did not show any pH-responsive drug release. Mechanistic studies using confocal laser scanning microscopy (CLSM) and small angle X-ray scattering (SAXS) analyses showed that increases in particle porosity and decreases in particle densities are directly linked to pH-responsive release properties. Therefore, the pH-responsive release mechanism was identified as diffusion controlled in a novel and unique approach by linking scattering results with in-vitro studies. Finally, cytotoxicity studies using the human monocytic THP-1 cell line indicated non-toxic behavior of the drug loaded nanocapsules when applied in a concentration of 62.5 µg mL. Based on the obtained release properties of HSA-SF nanocapsules formulations and the results of in-vitro MTT assays, formulations containing 50% SF showed the highest requirements arguing for future in vivo experiments and application in the treatment of inflammatory diseases.
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http://dx.doi.org/10.1016/j.ejpb.2018.10.002 | DOI Listing |
Int J Biol Macromol
January 2025
Pharmacy School, Jinzhou Medical University, Jinzhou, China; Liaoning Provincial Collaborative Innovation Center for Medical Testing and Drug Research, Jinzhou Medical University, Jinzhou, China; Key Laboratory of Medical Tissue Engineering of Liaoning Province, Jinzhou Medical University, Jinzhou, China. Electronic address:
In this study, we developed calcium alginate-coated nanovesicles derived from macrophage membranes loaded with berberine (Ber@MVs-CA) for the oral treatment of ulcerative colitis (UC). Ber@MVs-CA demonstrates resistance to gastric acid and controlled drug release in the colonic pH environment, while actively targeting sites of ulcerative colitis injury. pH-responsive release of Ber in Ber@MVs-CA was confirmed through in vitro release experiments.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Faculty of Medicine, Macau University of Science and Technology, Taipa 999078, Macao; Zhuhai MUST Science and Technology Research Institute, Zhuhai 519031, Guangdong, China. Electronic address:
Fruit spoilage caused by microorganisms results in huge economic losses and health risks worldwide every year. To develop an intelligent antimicrobial material capable of responding to the physiological activity of postharvest fruits and releasing antibacterial agents on demand, we fabricated a pH-responsive film for the release of chlorine dioxide (ClO) using carboxymethyl cellulose (CMC) and sodium chlorite (NaClO) via the solution casting method, with a CMC:NaClO ratio of 1:2 w/w. An acid environment simulated by 4 % acetic acid activated 43 % of ClO released by the film within 7 days.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Chemistry, Sri Krishnadevaraya University, Ananthapur 515003, India. Electronic address:
Composite gels are a type of soft matter, which contains a continuous three-dimensional crosslinked network and has been embedded with non-gel materials. Compared to pure gels, composite gels show high flexibility and tunability in properties and hence have attracted extensive interest in applications ranging from cancer therapy to tissue engineering. In this study, we incorporated triethylenetetramine (TETA)-functionalized cobalt ferrite nanoparticles (ANPs) into a hydrogel consisting of sodium alginate (SA) and methyl cellulose (MC), and examined the resulting composite gels for controlled drug release.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Biological Science and Technology, Center for Intelligent Drug Systems and Smart Bio-devices (IDS2B), National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan.
The blood-brain barrier (BBB) remains a major obstacle for effective delivery of therapeutics to treat central nervous system (CNS) disorders. Although transferrin receptor (TfR)-mediated transcytosis is widely employed for brain drug delivery, the inefficient release of therapeutic payload hinders their efficacy from crossing the BBB. Here, we developed a pH-responsive anti-polyethylene glycol (PEG) × anti-TfR bispecific antibody (pH-PEG engager) that can complex with PEGylated nanomedicine at physiological pH to trigger TfR-mediated transcytosis in the brain microvascular endothelial cells, while rapidly dissociating from PEGylated nanomedicine at acidic endosomes for efficient release of PEGylated nanomedicine to cross the BBB.
View Article and Find Full Text PDFACS Biomater Sci Eng
January 2025
School of Biological Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India.
Melanoma, an aggressive skin cancer originating from melanocytes, presents substantial challenges due to its high metastatic potential and resistance to conventional therapies. Hydrogels, 3D networks of hydrophilic polymers with high water-retention capacities, offer significant promise for controlled drug delivery applications. In this study, we report the synthesis and characterization of hydrogelators based on the triazine molecular scaffold, which self-assemble into fibrous networks conducive to hydrogel formation.
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