We present an analytical treatment of diffusional release of a dispersed solute from a cylindrical non-erodible polymeric matrix and study the mechanism of diffusional release of solute from the matrix system as a function of solute loading parameter. The diffusion equation is solved exactly under perfect sink condition for certain concentration of solute in the form of cylindrical geometry. The numerical solution of diffusional release function as a function of time is found to be increased initially and then remain constant after certain time, tau(c). This tac(c) is found to be as a function of solute loading parameter. The asymptotic solutions of the diffusional release function is also presented.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1166/jnn.2012.6456 | DOI Listing |
Zhong Nan Da Xue Xue Bao Yi Xue Ban
August 2024
Xiangya Stomatological Hospital and Xiangya School of Stomatology, Central South University; Hunan Engineering Research Center for Oral Digital Intelligence and Personalized Medicine; Hunan 3D Printing Engineering Research Center of Oral Care; WANG Songling Academician Workstation for Oral-maxilofacial and Regenerative Medicine, Central South University, Changsha 410078.
Objectives: Drug-loaded mucoadhesive silk fibroin (SF) microneedle patch can overcome the limitations of low bioavailability and significant pain associated with traditional treatment methods, such as topical application or injection of triamcinolone for oral submucous fibrosis (OSF). However, these systems release the drug too quickly, failing to meet the clinical requirements. This study aims to construct a mucoadhesive SF microneedle patch pre-assembled with silk fibroin nanospheres (SFN) and explore its ability to sustain the release of triamcinolone in the treatment of OSF.
View Article and Find Full Text PDFAt the first synapse in the vertebrate retina, rod photoreceptor terminals form deep invaginations occupied by multiple second-order rod bipolar and horizontal cell (RBP and HC) dendrites. Synaptic vesicles are released into this invagination at multiple sites beneath an elongated presynaptic ribbon. We investigated the impact of this complex architecture on the diffusion of synaptic glutamate and activity of postsynaptic receptors.
View Article and Find Full Text PDFJ Gen Physiol
October 2024
Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, Melbourne, Australia.
Ca2+ release from the sarcoplasmic reticulum (SR) plays a central role in excitation-contraction coupling (ECC) in skeletal muscles. However, the mechanism by which activation of the voltage-sensors/dihydropyridine receptors (DHPRs) in the membrane of the transverse tubular system leads to activation of the Ca2+-release channels/ryanodine receptors (RyRs) in the SR is not fully understood. Recent observations showing that a very small Ca2+ leak through RyR1s in mammalian skeletal muscle can markedly raise the background [Ca2+] in the junctional space (JS) above the Ca2+ level in the bulk of the cytosol indicate that there is a diffusional barrier between the JS and the cytosol at large.
View Article and Find Full Text PDFDent Mater
November 2024
Faculty of Dentistry, National University of Singapore, Singapore; ORCHIDS: Oral Care Health Innovations and Designs Singapore, National University of Singapore, Singapore. Electronic address:
Objective: Acyclovir (ACY) is used to treat oral viral herpes but has low solubility and bioavailability. Stearic acid (SA) is lipophilic and can be combined with drugs. Therefore, this study aimed to characterize the properties of SA nanoparticles in increasing the cellular uptake of ACY by oral epithelial cells.
View Article and Find Full Text PDFDent Mater
July 2024
University of São Paulo School of Dentistry, Department of Biomaterials and Oral Biology, Av. Prof. Lineu Prestes, 2227, São Paulo, SP 05508-000, Brazil. Electronic address:
Objective: To investigate the effect of hydrophilic/permeable polymer matrices on water sorption/solubility (WS/SL), Ca release, mechanical properties and hydrolytic degradation of composites containing dicalcium phosphate dihydrate (DCPD) particles.
Methods: Six composites were tested, all with 10 vol% of glass particles and either 30 vol% or 40 vol% DCPD. Composites containing 1BisGMA:1TEGDMA in mols (at both inorganic levels) were considered controls.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!