Browsing by Subject "Controlled drug release"
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Item Open Access A sustainable solution to skin diseases: ecofriendly transdermal patches(MDPI AG, 2023-02-08) Yılmaz, Eylül Gülşen; Ece, Emre; Erdem, Özgecan; Eş, İsmail; İnci, FatihSkin is the largest epithelial surface of the human body, with a surface area of 2 m2 for the average adult human. Being an external organ, it is susceptible to more than 3000 potential skin diseases, including injury, inflammation, microbial and viral infections, and skin cancer. Due to its nature, it offers a large accessible site for administrating several medications against these diseases. The dermal and transdermal delivery of such medications are often ensured by utilizing dermal/transdermal patches or microneedles made of biocompatible and biodegradable materials. These tools provide controlled delivery of drugs to the site of action in a rapid and therapeutically effective manner with enhanced diffusivity and minimal side effects. Regrettably, they are usually fabricated using synthetic materials with possible harmful environmental effects. Manufacturing such tools using green synthesis routes and raw materials is hence essential for both ecological and economic sustainability. In this review, natural materials including chitosan/chitin, alginate, keratin, gelatin, cellulose, hyaluronic acid, pectin, and collagen utilized in designing ecofriendly patches will be explored. Their implementation in wound healing, skin cancer, inflammations, and infections will be discussed, and the significance of these studies will be evaluated with future perspectives.Item Open Access Boronic acid conjugated peptide amphiphile systems for controlled drug release(Bilkent University, 2017-08) Kara, Hatice KübraTargeted cancer drug delivery is still under investigation and scientists have been focusing on major differences between healthy and cancer tissue to develop novel effective therapies. The cancer microenvironment has different physiological properties than the healthy tissues, for instance, it has more acidic pH, and much of the attention has been given to developing stimuli responsive agents for targeted drug delivery applications. Boronic acid is one of the most well-known stimuli responsive molecule which can form reversible covalent bonds with vicinal diols such as saccharide or catechol, that achieves targeted cancer drug release in a pH dependent manner. At neutral pH, the bond formation is triggered; however, these bonds become weaker at slightly acidic environment. Boronic acid conjugated polymers have been frequently preferred for doxorubicin encapsulation, which is a widely used chemotherapeutic drug utilized to treat several cancer types. In this study, boronic acid and DOPA conjugated peptide amphiphiles were used as a biocompatible and biodegradable alternative to polymeric systems. Peptide amphiphiles self assemble to form peptide nanofibers via noncovalent interactions, such as hydrogen bonding, hydrophobic interactions, van der Waals forces and electrostatic interactions, where boronic acid/DOPA units remain on the exterior part of the nanofibers. In addition to noncovalent interactions, at physiological pH, boronic acid and DOPA moieties on the peptide surface form reversible covalent complexes, resulting in improved hydrogel strength, self-healing capacity and entrapment of doxorubicin inside the 3D-network. On the other hand, under acidic conditions, these interactions weaken and doxorubicin release is accelerated at tumor site. Reversible covalent interaction, secondary structure, morphological, mechanical, release profile analysis were performed on the system. Results showed that this system exhibits promising features that can be used for therapeutic applications.Item Open Access Injectable in situ forming microparticles: A novel drug delivery system(2012) Yapar, E. A.; Inal, Ö.; Özkan, Y.; Baykara, T.Pharmaceutical formulation research has recently been focusing on delivery systems which provide long therapeutic effects and reduced side effects, and involving simplified production stages and facilitated application process. In situ forming microparticle (ISM) systems, one of the latest approach in this field, offer a new encapsulation technique and meet the objectives stated above. Factors such as the carrier used to form the multiparticles, amount and type of drug and the vehicle type can be taken as the main performance criteria for these systems. Ongoing studies have shown that this new multiparticulate drug delivery system is suitable for achieving new implant delivery system with low risk of dose-dumping, capable of being modulated to exhibit varying release patterns, reproducible, easily applicable and welltolerated compared with classically surgical implants.Item Open Access Noncovalent functionalization of mesoporous silica nanoparticles with amphiphilic peptides(Royal Society of Chemistry, 2014) Sardan, M.; Yildirim, A.; Mumcuoglu, D.; Tekinay, A. B.; Güler, Mustafa O.The surface of mesoporous silica nanoparticles (MSNs) has been modified for enhancing their cellular uptake, cell targeting, bioimaging, and controlled drug release. For this purpose, covalent anchorage on the silica surface was predominantly exploited with a wide range of bioactive molecules. Here, we describe a facile self-assembly method to prepare a hybrid peptide silica system composed of octyl-modified mesoporous silica nanoparticles (MSNs) and peptide amphiphiles (PAs). The hydrophobic organosilane surface of mesoporous silica was coated with amphiphilic peptide molecules. The peptide functionalized particles exhibited good cyto-compatibility with vascular smooth muscle and vascular endothelial cells. The peptide coating also improved the cellular uptake of particles up to 6.3 fold, which is promising for the development of highly efficient MSN based theranostic agents. © 2014 the Partner Organisations.