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In the present work, we describe the fabrication of a thermosensitive hydrogel. To fabricate the hydrogel (Sq1@PNIPAAm), we opted to use biocompatible poly(N-isopropylacrylamide) (PNIPAM) and squaraine dye (Sq1) as the polymer and the crosslinker, respectively. It is noteworthy that Sq1@PNIPAAm can be loaded with fluorescein, and we evaluated the fluorescein release behavior of Sq1@PNIPAAm hydrogel. We noted that on demand sustainable release of fluorescein was feasible upon gradual heating of Sq1@PNIPAAm hydrogel. Furthermore, Sq1@PNIPAAm hydrogels can be used as photosensitizers pertinent to photodynamic therapy (PDT). Our results show that hydrogel possesses favorable biological safety for use in in vitro anticancer studies. In vitro experiments confirmed that Sq1@PNIPAAm hydrogels could kill over 40% of cancer cells. Overall, we have successfully shown that Sq1@PNIPAAm enabled photodynamic therapy. Moreover, fluorescein loading into Sq1@PNIPAAm was possible, and it could be used to successfully accomplish temperaturecontrolled on-demand release. Given the abundance of low-cost, commercially accessible monomers available for use in hydrogel synthesis, this method offers access to a wide range of functional hydrogels for use in biomedical applications. [ABSTRACT FROM AUTHOR]

Nanoteknoloji, tıp bilimleri dahil olmak üzere hayatın hemen her alanında önemli bir rol oynamıştır. Nanoteknolojik ürünlerin önemli bir sınıfını da nanofiberler oluşturmaktadır. Nanofiberlerle biyomedikal uygulamalarla ilgili başlıca araştırma hatları, kontrollü ilaç salım uygulamaları için antitümör ilaçların kapsüllenmesini, doku mühendisliği ve rejeneratif tıp için iskele yapılarını ve ayrıca kanser tümörlerinin azaltılmasında uygulanacak manyetik veya plazmonik hipertermiyi kapsamaktadır. Özellikle, kemoterapide kullanılan genel antikanser ilaçlarının, yüksek doz kullanımları ile ciddi yan etkilerle ilişkili olması ve normal hücrelere de zarar vermesinden dolayı, kontrollü ve sürekli bir ilaç salınımı, faydalar sağlamaktadır. Bu amaçla kullanılan antikanser ilacı yüklü nanofiberler, ilacın daha uzun süre korunmasını ve daha az ilaçla sonuca ulaşılmasını sağladığı için önemli sonuçlara ulaşılmıştır. Elektrospun nanofiberler, çok geniş yüzey alanına, kontrol edilebilir gözenek boyutuna ve ayarlanabilir ilaç salım profillerine sahip olup, gelecek vadeden adaylardır. Elektroeğirme yönteminin nanofiber yapıları üretmede sunduğu göreceli kolaylık, farklı polimer yapıların, polimer veya inorganik maddelerin kompozit olarak kullanılabilmeleri, farklı boyut, şekil, gözenek boyutlarında üretilebilmeleri, dış ve/veya iç uyaranlara (pH, sıcaklık, manyetik alan, ışık vb.) yanıt verme yeteneklerine sahip olabilmeleri, yeni stratejilerin ve yeni araştırmaların sayısını oldukça arttırmaktadır. Bunun yanında, nanofiberlerin kanser tedavisinde uygulanmasına ilişkin çok sayıda araştırma raporu bulunmaktadır. Bu derleme makale, başarılı kanser tedavisi için rapor edilmiş, bazı elektrospun nanofiberlere genel bir yaklaşımla odaklanmaktadır.

Herbal sources contain a variety of bio-actives, which are also called phytochemicals. Many of the herbal bio-actives have therapeutic effects and distinguished chemical properties that allow them favorable candidates for phytomedicines. The history of traditional herbal medicines, which are the precursors of phytopharmaceuticals, dates back to ancient times. Today, many of the officially approved and widely used medicines are produced by isolating active substances from herbal sources. Although traditional pharmaceutical dosage forms such as tablets, capsules, syrups, solutions, decoctions and ointments are still used today, problems related with the absorption, biotransformation and stability of phytochemicals reduces the efficacy, bioavailability and in some cases safety of herbal medicines. Also, conventional pharmaceutical dosage forms are often providing an immediate release of phytoconstituents. Besides the use of advanced drug delivery systems offer advantages to overcome mentioned problems, they also provide extended release with maximum efficacy associated with minimum side effects. Researches on development of herbal formulations by using novel drug delivery systems have gain attention and the use of nanotechnology-based systems have special attention. One of the nano drug carrier systems is nanofibers which have unique properties making them widely used in different treatments such as infections, allergy, rheumatic diseases, inflammatory diseases, cancers, etc. In this study, the use of the nanofiber-based carrier systems to deliver herbal bio-actives through various drug application routes is overviewed. [ABSTRACT FROM AUTHOR]

Controlled release, on the contrary traditional treatment, means the gradual release of a substance from a system in order to maintain its concentration in a medium over a period of time. In drug release systems, the controlled release of the drug to the diseased area has importance in terms of treatment and toxicity. Especially drugs with high toxic properties such as 5-Fluorouracil (5-FU) have an important place in controlled drug release technology. In order to complete the treatment successfully, it is important to develop controlled drug release systems to eliminate the possible side effects of anticancer drugs such as 5-FU and to increase the therapeutic effect. The aim of this study is to develop a unique biodegradable and biocompatible bionanocomposite film for the controlled release of 5-FU. For this purpose, bentonite loaded chitosan hydroxypropyl methylcellulose bionanocomposite films were synthesized using solution casting and solvent evaporation techniques. The chemical bond structure of the bionanocomposite films and the effect of bentonite addition on the amine and hydroxyl groups in the structure were determined by Fourier transform infrared. Morphological properties and compatibility of polymers and bentonite were characterized by using scanning electron microscopy. The degree of sorption of the bionanocomposite films was evaluated by swelling tests. As the bentonite content in the nanocomposite film increased from 5% to 25%, the sorption degree of film increased from 2.99% to 65.05%. In addition, the effects of bentonite addition of the synthesized bionanocomposite films and pH of medium on the 5-FU loading and encapsulation efficiency were investigated. Controlled release studies were carried out by using 5-FU loaded nanocomposite films. The obtained results showed that the usage of bentonite in nanocomposite drug carrier films were improved the release properties. After four days, a release value was obtained as 40.12% at pH=7.4 in the 5 wt. % bentonite loaded films. [ABSTRACT FROM AUTHOR]

Objectives: Polyurethanes (PUs) are a popular choice for composing nanofibers due to their spinnability, biocompatibility, high chemical stability, and good mechanical and elasticity properties. The desired release behaviors are also achieved by using combinations of PUs and various polymers. In this study, we investigated effects of polyvinylpyrrolidone (PVP) and ethyl cellulose (EC) on PU electrospun nanofibers in terms of morphological structures and drug release characteristics. Materials and Methods: Nanofibers were prepared using blends of PU with either EC or PVP in different ratios by electrospinning. The effects of PVP or EC on the morphology and diameter of the prepared nanofibers were examined with scanning electron microscope (SEM). The compatibility of the components used in the formulations of nanofibers was determined by attenuated total reflection (ATR)-fourier-transform infrared (FTIR). Donepezil hydrochloride (DNP), a water soluble compound, was selected as a model drug to examine its release characteristics from both PU/PVP and PU/EC electrospun nanofibers. In vitro drug release studies from electrospun nanofibers were performed according to the method defined in the monograph as the "paddle over disk method" of United States Pharmacopeia 38. Results: The SEM images showed that addition of EC or PVP to PU solutions did not affect the generation of nanofibers, and those formed had a smooth surface without beads in nanoscale. The ATR-FTIR spectra disclosed that EC and PVP were separately incorporated into the PU matrix. The in vitro release data indicated that the presence of EC or PVP in PU nanofibers dramatically changed the release behavior of DNP. PU/EC nanofibers (F4) provided sustained drug release with the Korsmeyer-Peppas drug release kinetic mechanism, in which the release rate was controlled by diffusion of the drug, while all of the PU/PVP nanofibers exhibited fast drug release. Conclusion: Overall, these characteristics of PU/EC (10/8) electrospun nanofibers has suggested their potential use as a drug carrier from which water-soluble drug release may occur in a sustained fashion. [ABSTRACT FROM AUTHOR]

Objectives: Azithromycin dihydrate is a macrolide antibiotic used for the treatment of several types of bacterial infections. The drug shows low oral bioavailability due to its low solubility. In the present work solid lipid nanoparticles of azithromycin dihydrate were formulated, keeping in view enhancement of the solubility and rate of dissolution of the drug. Materials and Methods: Azithromycin dihydrate loaded stearic acid nanoparticles were formulated by high shear homogenization using three different surfactants, namely Tween 20, poloxamer 188, and poloxamer 407, at a varied lipid surfactant ratio while keeping the quantities of the active ingredient constant. Twelve such formulations were prepared. The nanoparticles obtained were evaluated for drug content, % drug loading, % entrapment efficiency, particle size analysis, zeta potential, surface morphology, Fourier transmission infrared spectroscopy, in vitro drug release, and stability. Results: All the formulations showed good entrapment efficiency and high percentage of in vitro release with a particle size suitable for lymphatic absorption. The nanoparticles formulated with poloxamer 188 showed better characteristics compared to the other surfactants. Conclusion: This study indicates that stearic acid nanoparticles of azithromycin dihydrate prepared by high shear homogenization can be successively used for improvement of dissolution and thereby oral bioavailability of the drug. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study was to prepare a controlled release system, which could be used in medical applications in order to treat infections at the host region. Methods: Microlayer films were prepared via solvent casting method. Films with 3-layers were prepared by using chitosan (CHI), gelatin (GEL) and alginate (ALG) in the form of CHI /ALG/CHI and CHI-GEL /ALG/CHI-GEL with or without ceftriaxone sodium (CS) which is loaded in the middle ALG layer. All films were crosslinked by exposing them to glutaraldehyde (GA) vapor for different (2 h, 10 h or 24 h) durations. Mechanical properties of the films and release kinetics of CS at three different pH conditions (pH 5.5, 7.4, and 10.0) were investigated. The antibacterial efficiency of the released CS against Escherichia coli was examined via agar spot test. Results: The results indicated that the presence of GEL in the upper and lower layers of the 3-layer construct prevented fragility and increased the mechanical strength of the films, whereas the presence of CS in the middle layer caused decrease in the mechanical properties. Crosslinking with GA did not demonstrate a significant effect on the release profile of CS, but due the interaction of chitosan with alginate and CS, the drug release was delayed. Antibacterial tests which were carried out by using the released media of drug loaded films displayed inhibition zone in agar spot tests against E. coli. Conclusion: It was concluded that multilayered films prepared by solvent casting can be good candidates as drug carrier devices in medical applications. [ABSTRACT FROM AUTHOR]

In this study, the electrospun fibers of chitosan (Ch)/poly (methyl methacrylate) (PMMA) (K1), Ch/PMMA (K2) containing 0.3 wt.% ibuprofen (Ibu) and Ch/PMMA (K3) containing 0.6 wt.% Ibu were obtained for the first time by electrospinning technique. The controlled release of ibuprofen from the K2 and K3 fiber surfaces was investigated by quartz crystal microbalance (QCM) system. The results of QCM were compared with the results of ultraviolet-visible (UV-Vis) absorption spectroscopy. The morphological characteristics of the biocompatible fibers were characterized by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). It was observed that the best drug release mechanism from the drug release kinetics graphs was attributed to the K2 fiber structure obtained from the Ch/PMMA solution containing 0.3 wt.% Ibu and this was found to be the optimal drug concentration. [ABSTRACT FROM AUTHOR]

In this study, graft polymerization of glycidyl methacrylate (GMA) monomer onto crosslinked poly (vinyl alcohol), CPVA was carried and then it was aimed to be functionalized by modifying with amine groups. The characterization of the obtained samples was carried out by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). It was found that the equilibrium degree of swelling (SDD) of the functionalized sample has changed at different pH's, the highest SSD value was obtained at pH 2.1. Trypan blue (TB) as a anionic drug and 5-flurasil (5-FU) as a non-ionic drug were chosen as model drugs to perform the drug loading and release studies. As a result, it has been observed that the obtained samples and drugs have different charge groups so the amounts of loaded drugs and therefore the amounts of the releases differ. [ABSTRACT FROM AUTHOR]