Controlled Drug Release System Research Articles

A Bone-Penetrating Precise Controllable Drug Release System Enables Localized Treatment of Osteoporotic Fracture Prevention via Modulating Osteoblast-Osteoclast Communication.

Improving local bone mineral density (BMD) at fracture-prone sites of bone is a clinical concern for osteoporotic fracture prevention. In this study, a featured radial extracorporeal shock wave (rESW) responsive nano-drug delivery system (NDDS) is developed for local treatment. Based on a mechanic simulation, a sequence of hollow zoledronic acid (ZOL)-contained nanoparticles (HZNs) with controllable shell thickness that predicts various mechanical responsive properties is constructed by controlling the deposition time of ZOL and Ca2+ on liposome templates. Attributed to the controllable shell thickness, the fragmentation of HZNs and the release of ZOL and Ca2+ can be precisely controlled with the intervention of rESW. Furthermore, the distinct effect of HZNs with different shell thicknesses on bone metabolism after fragmentation is verified. In vitro co-culture experiments demonstrate that although HZN2 does not have the strongest osteoclasts inhibitory effect, the best pro-osteoblasts mineralization results are achieved via maintaining osteoblast-osteoclast (OB-OC) communication. In vivo, the HZN2 group also shows the strongest local BMD enhancement after rESW intervention and significantly improves bone-related parameters and mechanical properties in the ovariectomy (OVX)-induced osteoporosis (OP) rats. These findings suggest that an adjustable and precise rESW-responsive NDDS can effectively improve local BMD in OP therapy.

LECITHIN MICROEMULSIONS WITH GAC OIL AND TURMERIC ESSENTIAL OIL

It has been shown that water-in-oil microemulsions in lecithin–oleic acid–Vaseline oil–vegetable oil–essential oil–water systems can be obtained using the oil of a tropical plant, gac (Momordica cochinchinensis), and turmeric essential oil (Curcuma longa). Water (at least 6.5 wt %) can be incorporated into the microemulsions at a lecithin concentration in the organic phase of 20 wt %, a Vaseline oil-to-gac oil ratio of 1 : 1 (weight/weight), and an oleic acid-to-lecithin molar ratio of 0.2–0.8. Depending on the contents of water and lecithin, the hydrodynamic diameter of microemulsion droplets ranges from 3 to 21 nm. FTIR spectroscopy has been employed to show that, for the microemulsion with W = 14, the fraction of bulk (free) water in the droplets is 36.5 mol %, the fraction of hydration water (bound to polar groups of the surfactants) is 55.0 mol %, and the fraction of water trapped between hydrocarbon chains is 8.5 mol %. Using the dialysis method and a water-soluble dye Rhodamine C as a model, it has been shown that the rate of its transfer from the microemulsion to the physiological solution is 15.4 × 10–3 g/(m2 h). Approximately 3.2% of the dye has been found to be released over 6 h, thus making it possible to develop controlled drug release systems.

Hydrogel systems for targeted cancer therapy.

When hydrogel materials with excellent biocompatibility and biodegradability are used as excellent new drug carriers in the treatment of cancer, they confer the following three advantages. First, hydrogel materials can be used as a precise and controlled drug release systems, which can continuously and sequentially release chemotherapeutic drugs, radionuclides, immunosuppressants, hyperthermia agents, phototherapy agents and other substances and are widely used in the treatment of cancer through radiotherapy, chemotherapy, immunotherapy, hyperthermia, photodynamic therapy and photothermal therapy. Second, hydrogel materials have multiple sizes and multiple delivery routes, which can be targeted to different locations and types of cancer. This greatly improves the targeting of drugs, thereby reducing the dose of drugs and improving treatment effectiveness. Finally, hydrogel can intelligently respond to environmental changes according to internal and external environmental stimuli so that anti-cancer active substances can be remotely controlled and released on demand. Combining the abovementioned advantages, hydrogel materials have transformed into a hit in the field of cancer treatment, bringing hope to further increase the survival rate and quality of life of patients with cancer.

Stimulus-Responsive Ultrathin Films for Bioapplications: A Concise Review.

The term "nanosheets" has been coined recently to describe supported and free-standing "ultrathin film" materials, with thicknesses ranging from a single atomic layer to a few tens of nanometers. Owing to their physicochemical properties and their large surface area with abundant accessible active sites, nanosheets (NSHs) of inorganic materials such as Au, amorphous carbon, graphene, and boron nitride (BN) are considered ideal building blocks or scaffolds for a wide range of applications encompassing electronic and optical devices, membranes, drug delivery systems, and multimodal contrast agents, among others. A wide variety of synthetic methods are employed for the manufacturing of these NSHs, and they can be categorized into (1) top-down approaches involving exfoliation of layered materials, or (2) bottom-up approaches where crystal growth of nanocomposites takes place in a liquid or gas phase. Of note, polymer template liquid exfoliation (PTLE) methods are the most suitable as they lead to the fabrication of high-performance and stable hybrid NSHs and NSH composites with the appropriate quality, solubility, and properties. Moreover, PTLE methods allow for the production of stimulus-responsive NSHs, whose response is commonly driven by a favorable growth in the appropriate polymer chains onto one side of the NSHs, resulting in the ability of the NSHs to roll up to form nanoscrolls (NSCs), i.e., open tubular structures with tunable interlayer gaps between their walls. On the other hand, this review gives insight into the potential of the stimulus-responsive nanostructures for biosensing and controlled drug release systems, illustrating the last advances in the PTLE methods of synthesis of these nanostructures and their applications.

Investigation of the Therapeutic Effects of Palbociclib Conjugated Magnetic Nanoparticles on Different Types of Breast Cancer Cell Lines.

Drug targeting and controlled drug release systems in cancer treatment have many advantages over conventional chemotherapy in terms of limiting systemic toxicity, side effects, and overcoming drug resistance. In this paper, fabricating nanoscale delivery system composed of magnetic nanoparticles (MNPs) covered with poly-amidoamine (PAMAM) dendrimers and using its advantages were fully used to help the chemotherapeutic drug, Palbociclib, effectively reach tumors, specifically and stay stable in the circulation longer. In order to determine whether conjugate selectivity can be increased for the specific drug type, we have reported different strategies for loading and conjugation of Palbociclib to different generations of magnetic PAMAM dendrimers. The best method leading to the highest amount of Palbociclib conjugation was chosen, and the characterization of the Palbociclib conjugated dendrimeric magnetic nanoparticles (PAL-DcMNPs) were performed. In vitro pharmacological activity of the conjugation was demonstrated by measuring the cell viability and lactate dehydrogenase (LHD) release. Obtained results indicated that PAL-DcMNPs treatment of the breast cancer cell lines, leads to an increase in cell toxicity compared to free Palbociclib. The observed effects were more evident for MCF-7 cells than for MDA-MB231 and SKBR3 cells, considering that viability decreased to 30% at 2.5µM treatment of PAL-DcMNPs at MCF-7 cells. Finally, in Palbociclib and PAL-DcMNPs treated breast cancer cells, the expression levels of some pro-apoptotic and drug resistance related genes were performed by RT-PCR analysis. Our knowledge indicates that the proposed approach is novel, and it can provide new insight into the development of Palbociclib targeting delivery system for cancer treatment.

Smart Drug-Delivery System of Upconversion Nanoparticles Coated with Mesoporous Silica for Controlled Release.

Drug-delivery vehicles have garnered immense interest in recent years due to unparalleled progress made in material science and nanomedicine. However, the development of stimuli-responsive devices with controllable drug-release systems (DRSs) is still in its nascent stage. In this paper, we designed a two-way controlled drug-release system that can be promoted and prolonged, using the external stimulation of near-infrared light (NIR) and protein coating. A hierarchical nanostructure was fabricated using upconversion nanoparticles (UCNPs)-mesoporous silica as the core-shell structure with protein lysozyme coating. The mesoporous silica shell provides abundant pores for the loading of drug molecules and a specific type of photosensitive molecules. The morphology and the physical properties of the nanostructures were thoroughly characterized. The results exhibited the uniform core-shell nanostructures of ~four UCNPs encapsulated in one mesoporous silica nanoparticle. The core-shell nanoparticles were in the spherical shape with an average size of 200 nm, average surface area of 446.54 m2/g, and pore size of 4.6 nm. Using doxorubicin (DOX), a chemotherapy agent as the drug model, we demonstrated that a novel DRS with capacity of smart modulation to promote or inhibit the drug release under NIR light and protein coating, respectively. Further, we demonstrated the therapeutic effect of the designed DRSs using breast cancer cells. The reported novel controlled DRS with dual functionality could have a promising potential for chemotherapy treatment of solid cancers.

Preliminary Assessment of Intramuscular Depot of Lipid-Based Decoquinate Formulation for Long-Term Chemoprophylaxis of Malaria.

Sustained-release formulations of decoquinate were evaluated for the long-term prophylaxis of malaria. In the initial experiment, mice were protected from liver-stage Plasmodium infection by intramuscular administration of a lipids-based formulation at a dose of decoquinate 200 mg/kg. The mice that were inoculated with Plasmodium berghei sporozoites 34 days after the administration of a one-time drug dose were continuously monitored for 60 days and shown to be free of Plasmodium parasites. The optimized formulation for the sustained release of decoquinate was prepared by hot melt extrusion, constructed by lipids including cholesterol and mono or diglycerides, and had a drug load of 20 to 40% and particle size of 30 to 50 μm. Decoquinate of the lipids-based formulation was slowly released in vitro at a constant rate for the duration of two months, and was examined and continuously exposed at a therapeutic level in the blood for as long as 4 to 6 months. Further evaluation showed that the lipids-based formulation at doses of decoquinate 100 to 150 mg/kg could protect mice from Plasmodium infection for a period of 120 days. It is the first time that cholesterol has been used for a controlled drug delivery system of decoquinate. The results may provide useful information, not only for preparing a formulation of long-acting decoquinate but also in general for developing a controlled drug release system. The one-time administration of pharmaceutical agents in such a slow-release system may serve patients with no concerns about compliance.

Toward Efficient Wound Management: Bioinspired Microfluidic and Microneedle Patch.

Microneedle (MN) patches hold demonstrated prospects in intelligent wound management. Herein, inspired by the highly folded structure of insect wings, a three-dimensional (3D) origami MN patch with superfine miniature needle structures, microfluidic channels, and multiple functions wasreported to detect biomarkers, release drugs controllably and monitor motions to facilitate wound healing. By simply replicating the pre-stretched silicone rubber (Ecoflex) molds patterned by a laser engraving machine, the superfine structure MN patch with microfluidic channels wasobtained from the restored molds. The bioinspired origami structure endows the MN patch with a high degree of functional integration, including microfluidic channels and electrocircuits. The microfluidic channels combined with the pH value and glucose concentration indicators enable the patch with the capability of biomarker sensing detection. Porous structures, a temperature-responsive hydrogel, and a photothermal-sensitive agent are utilized to form a controllable drug release system on the MN patch. Meanwhile, MXene electrocircuits wereprinted on the MN patch for motion sensing. In addition, the ability of the MN patch to accelerate wound healing wasdemonstrated by a mouse model experiment with full-thickness skin wounds. These results indicate that the multifunctional 3D origami MN patch is a valuable intelligent strategy for wound management.

Nanoparticle-Delivered Transforming Growth Factor-β1 siRNA Induces PD-1 against Gastric Cancer by Transforming the Phenotype of the Tumor Immune Microenvironment.

Immune checkpoint blockade (ICB) is currently considered to be an important therapeutic method, which obtained FDA approval for clinical use in gastric cancer in 2017. As a new mechanism, it was found that the effect of αPDL1 could be improved by blocking the TGF-β1 signaling pathway, which converts the tumor immune microenvironment from the "immune-excluded phenotype" to the "immune-inflamed phenotype". Based on this phenomenon, this project was designed to prepare TGF-β1-siRNA-loaded PEG-PCL nanoparticles conjugated to αPDL1 (siTGF-β1-αPDL1-PEG-PCL) since we have linked similar antibodies to PEG-PCL previously. Therefore, MFC tumor-engrafted mice were established to simulate the biological characteristics of converting the phenotype of the immune microenvironment, and to study the anti-tumor effect and possible molecular mechanism. In this study, αPDL1 antibody conjugates markedly increased the cell uptake of NPs. The produced αPDL1-PEG-PCL NPs efficiently reduced the amounts of TGF-β1 mRNA in MFC cells, converting the immune microenvironment of MFC tumors engrafted mice from the "immune-excluded phenotype" to the "immune-inflamed phenotype". PDL1-harboring gastric cancer had increased susceptibility to αPDL1. The value of this drug-controlled release system targeting the tumor microenvironment in immune checkpoint therapy of gastric cancer would provide a scientific basis for clinically applying nucleic acid drugs.

Chiral nanocrystals grown from MoS2 nanosheets enable photothermally modulated enantioselective release of antimicrobial drugs

The transfer of the concept of chirality from molecules to synthesized nanomaterials has attracted attention amongst multidisciplinary teams. Here we demonstrate heterogeneous nucleation and anisotropic accumulation of Au nanoparticles on multilayer MoS2 planes to form chiroptically functional nanomaterials. Thiol amino acids with chiral conformations modulate asymmetric growth of gold nanoarchitectures on seeds of highly faceted Au/MoS2 heterostructures. Consequently, dendritic plasmonic nanocrystals with partial chiral morphologies are synthesized. The chirality of dendritic nanocrystals inherited from cysteine molecules refers to the structural characteristics and includes specific recognition of enantiomeric molecules. With integration of the intrinsic photothermal properties and inherited enantioselective characteristics, dendritic Au/MoS2 heterostructures exhibit chirality-dependent release of antimicrobial drugs from hydrogel substrates when activated by exogenous infrared irradiation. A three-in-one strategy involving synthesis of chiral dendritic heterostructures, enantioselective recognition, and controlled drug release system is presented, which improves nanomaterial synthetic technology and enhances our understanding of crucial chirality information.

Monitoring of silica colloidal crystal-embedded chitosan hydrogel films swelling and its drug release application

The hydrogels, because of their swelling properties in response to the environmental stimulus, are being widely considered for the design of controlled drug release systems. To meet the need for developing effective drug delivery methods, we developed special silica colloidal crystal (SCC)-embedded chitosan hydrogel films. The SCC films served as an interference substrate and drug storage layer, while the chitosan hydrogel served as a cover to regulate the drug release. The optical interferometry was performed to dynamically monitor the volume phase transition of chitosan hydrogel response to pH stimulation. Furthermore, the effects of crosslinking ratio and hydrogel thickness on the swelling properties of chitosan hydrogel were also evaluated. More importantly, the pH-responsive swelling of chitosan hydrogel was used to slowly release indomethacin. This system may provide support for drug delivery studies, therefore further expected to apply in the enhancement of the treatment efficiency of new drug therapies.

Electrospun poly(l‐lactide‐co‐ε‐caprolactone)/gelatin core–shell nanofibers encapsulated with doxorubicin hydrochloride as a drug delivery system

AbstractAdvanced application of coaxial electrospinning nanofibers in controlled drug release systems has gathered much attention since they have had a tunable structure for tailored release of drugs, including various proteins, growth factors, antibacterial and anticancer agents. The composite polymer poly(l‐lactide‐co‐ε‐caprolactone) (PLCL) blended with gelatin (GE) was used as the shell material to electrospin core–shell nanofibers. Model drug doxorubicin hydrochloride (DOX) was encapsulated in the core layers. The morphology and core–shell structure were evaluated by SEM and TEM respectively. The existence of DOX in the inner part of DOX/PLCL/GE nanofibers could be proved by Fourier transform infrared spectroscopy results. The water contact angle test results indicated that DOX/PLCL/GE nanofibers all possess good hydrophilicity with water contact angles as low as 51.2°. The in vitro release results indicated that the DOX/PLCL/GE nanofibers showed a sustained release profile for 480 h. The fitting results showed that the release kinetics of DOX from nanofibers was consistent with a Ritger–Peppas model, presenting a typical Fickian diffusion mechanism. Overall, the DOX/PLCL/GE core–shell nanofibers showed regulable mechanical properties and could be used as a promising drug release system for drug sustained release and tissue engineering. © 2022 Society of Chemical Industry.

Titanium surface polyethylene glycol hydrogel and gentamicin-loaded cross-linked starch microspheres release system for anti-infective drugs

Objective To design and construct a hydrogel drug-controlled release system loaded with gentamicin on a titanium surface, and to evaluate the in vitro drug release behaviour and antibacterial properties and biocompatibility of the controlled release system. Methods Titanium (Ti) surface was coated with poly dopamine (PDA) substrate, and then polyethylene glycol (PEG) was attached to PDA. The composite drug microsphere controlled release layer formed by gentamicin (GEN) and cross-linked starch (CSt) were subsequently covered with poly lactic⁃co⁃glycolic acid (PLGA) as a barrier to construct a Ti-GEN-Cst-PLGA anti-infective drug controlled release system. Results The hydrogel drug release system was successfully constructed. The results of in vitro anti-staphylococcus aureus (SAU) assay, anti-staphylococcus epidermidis (SEP) assay and anti-Escherichia coli (ECO) assay showed that Ti-GEN-Cst-PLGA could effectively inhibit the growth of three bacteria. Assay in the New Zealand rabbit found that Ti-GEN-Cst-PLGA could promote wound healing at the 3rd week after implantation, and the pathology assay found that the Ti-GEN-Cst-PLGA group had less inflammatory reactions and significant tissue proliferation at the endophyte contact surface. Conclusion Ti-GEN-Cst-PLGA can effectively inhibit the inflammatory response and promote wound healing, or may be a potential treatment for orthopaedic endophytes.

Polylactic acid/silk fibroin composite hollow fibers as excellent controlled drug release systems

AbstractPolylactic acid (PLA) and silk fibroin (SF) have been widely used in biomedical applications because of their excellent biocompatibility and degradability. In this study, PLA and SF were used as raw materials to prepare hollow fibers with a skin‐core structure by wet spinning technology. Scanning electron microscopy observations revealed that the structure of hollow fibers became increasingly uniform with increasing silk fibroin mass fraction. Tensile test results showed that with the increase of silk fibroin content, the elastic modulus of hollow fibers decreased and their tensile properties improved. The results of hollow fibers degradation experiments revealed that increasing the content of silk fibroin can effectively shorten the degradation time of hollow fibers. Ultraviolet spectrophotometry was used to measure the absorbance of tetracycline hydrochloride in phosphate buffer saline and calculate its release rate in hollow fibers with different silk fibroin contents, the result is HFs‐9 > HFs‐7 > HFs‐0 > HFs‐5 > HFs‐3. The PLA/SF controlled drug release system has precise controlled release of the drug, realizes the separation of the drug from the controlled release system, and solves the problem of sudden drug release. In addition, the controlled release system is non‐toxic, degradable, and has excellent mechanical properties.

Drug-Inclusive Inorganic-Organic Hybrid Systems for the Controlled Release of the Osteoporosis Drug Zoledronate.

Bisphosphonates (BPs) are common pharmaceutical treatments used for calcium- and bone-related disorders, the principal one being osteoporosis. Their antiresorptive action is related to their high affinity for hydroxyapatite, the main inorganic substituent of bone. On the other hand, the phosphonate groups on their backbone make them excellent ligands for metal ions. The combination of these properties finds potential application in the utilization of such systems as controlled drug release systems (CRSs). In this work, the third generation BP drug zoledronate (ZOL) was combined with alkaline earth metal ions (e.g., Sr2+ and Ba2+) in an effort to synthesize new materials. These metal–ZOL compounds can operate as CRSs when exposed to appropriate experimental conditions, such as the low pH of the human stomach, thus releasing the active drug ZOL. CRS networks containing Sr2+ or Ba2 and ZOL were physicochemically and structurally characterized and were evaluated for their ability to release the free ZOL drug during an acid-driven hydrolysis process. Various release and kinetic parameters were determined, such as initial rates and release plateau values. Based on the drug release results of this study, there was an attempt to correlate the ZOL release efficiency with the structural features of these CRSs.

Progress of Hollow Materials in Diagnosis of Covid-19

Since the outbreak of COVID-19 in Wuhan, China, it has dramatically changed the global geopolitics, economics, and even society standard norms. The present world scenario is changed regarding business, traveling, and education. Rapid global dissemination and the high mortality rate of coronaviruses are the greatest challenges for drug developers. It will be moving forward toward the identification and treatment of emerging coronaviruses with the aid of nanotechnology. The COVID-19 pandemic raised the question of researchers’ capability to manage this dilemma in a short period. In the present review, we described how hallow material could be developed as a pro-drug that shows an excellent therapeutic effect. Hollow nanoparticles that exploration of antiviral or diagnostic agents against emerging coronaviruses. Hollow nanomaterials in vaccine development are essential because hollow nanocomposites are suitable for mimicking viral structures and antigen delivery. A biosensor that generates a signal from a transducer for comparing and analyzing biological conjugates such as cell receptors, antibodies, RNA, DNA, and nucleic acids. Different biosensors, such as graphene-based biosensors, nanoplasmonic sensor chips, nanomaterial biosensors, electrochemical biosensors, dual modality biosensors, and optical biosensors, have several advantages, characteristics, and a wide range of applications, most remarkably in medical treatment and are used for monitoring and diagnosis. This review focuses on modern experimental studies to identify intelligent and innovative bio/nanomaterials and matrices for developing targeted and controlled drug release systems, nanosensors and nanovaccines to combat pathogenic viruses.

Hypoxia-Activated PEGylated Paclitaxel Prodrug Nanoparticles for Potentiated Chemotherapy.

Developing controlled drug-release systems is imperative and valuable for increasing the therapeutic index. Herein, we synthesized hypoxia-responsive PEGylated (PEG = poly(ethylene glycol)) paclitaxel prodrugs by utilizing azobenzene (Azo) as a cleavable linker. The as-fabricated prodrugs could self-assemble into stable nanoparticles (PAP NPs) with high drug content ranging from 26 to 44 wt %. The Azo group in PAP NPs could be cleaved at the tumorous hypoxia microenvironment and promoted the release of paclitaxel for exerting cytotoxicity toward cancer cells. In addition, comparative researches revealed that the PAP NPs with the shorter methoxy-PEG chain (molecular weight = 750) possessed enhanced tumor suppression efficacy and alleviated off-target toxicity. Our work demonstrates a promising tactic to develop smart and simple nanomaterials for disease treatment.

A smart tri-layered nanofibrous hydrogel thin film with controlled release of dual drugs for chemo-thermal therapy of breast cancer

A tri-layered nanofibrous hydrogel thin film with temperature sensitivity is introduced as a new controlled drug release system to treat breast cancer. A simultaneous heat generation with the tunable release of dual drugs is observed in response to visible light radiation. A tri-layered nanofibrous sheet was fabricated through sequential electrospinning the blends of Au@Chit@DOX-loaded poly(N-isopropylacrylamide-co-N-methylol acrylamide) (poly (NIPAAm-co-NMA)) and Curcumin-loaded poly (vinyl alcohol) (Cu-loaded PVA), where the Cu-loaded PVA nanofibers (NFs) are sandwiched between two layers of Au@Chit@DOX-loaded poly (NIPAAm-co-NMA) NFs. After thermal crosslinking of the tri-layered nanofibrous sheet, the nanofibrous hydrogel thin film is obtained. FTIR/ATR, UV–Vis, Photoluminescence, and PXRD analyses were used for characterizing. PVA NFs and poly (NIPAAm-co-NMA) NFs were observed in the average diameters of 358 and 212 nm, respectively, and Au@Chit@DOX nanoparticles (NPs) appeared as local thickening inside the NFs. The distribution of drugs was visualized with confocal images. The thermal stability up to 295 °C and tensile strength of 0.65 MPa with 99.36% elongation were reported for the nanofibrous hydrogel thin film. Unlike the fast release of drugs from the nanofibrous sheet, a controlled release of drugs was observed from the nanofibrous hydrogel thin film at 45 °C and under visible light radiation. 52% at 45 °C and 55% under light radiation were reported for the Cur release and 86% at 45 °C and 88% under light radiation were observed for the release of DOX within 18 h. The in vitro cell viability results under light radiation displayed a chemo-thermal therapy over breast cancer cells.

A pH-Sensitive Chitosan/Oxidized-Kappa-Carrageenan based Nano-Antibiotic for Sustained and Controlled Release of Amoxicillin

Nowadays antibiotic resistance is one of the most serious problems. Therefore, there is a need for sustained and controlled drug release systems for antibiotics. The aim of this study was to develop a nano-antibiotic system using biocompatible and antimicrobial polymers that are abundant in nature. Frequently used amoxicillin was chosen as the antibiotic. Before nanoparticle synthesis kappa-carrageenan was oxidized and 1.2% carboxyl, and 23.08% aldehyde groups were obtained, as confirmed by Fourier-transform infrared spectroscopy. A combination of polyelectrolyte complexation and ionic gelation was occurred in the nanoparticle synthesis. For the optimal temperature, CaCl2 concentration and polymer ratio of 37 °C, 1.5% and 6:1, respectively, the results of hydrodynamic size measurements indicated the size was 414.4 nm. Drug loading encapsulation was successful with an efficiency of 73.28%. Drug release was monitored for 95 h, and drug release was 93% and 85%, respectively, at pH 6.0 and pH 7.4. It is shown by the mathematical models that the drug release profile can be explained by the Higuchi and first-order models since R 2 values were higher than for the other models. As a result, it was observed that the obtained nano-antibiotic delivery system performed a long-term drug release of approximately 4 days in a pH-sensitive manner and would be a promising drug delivery system.

Preparation and characterization of electrospun PLGA-SF nanofibers as a potential drug delivery system

Currently drug-controlled release technology has gained a great deal of attention on the field of biomedicine. Nevertheless, most drug-controlled release systems usually require complex modification. Herein, the monolayer and multilayer structure nanofibers for drug delivery of acetylsalicylic acid (ASA), as a model drug, were fabricated using the one-step electrospinning technique for the first time, which was composed with the poly(lactic-co-glycolic acid) (PLGA) and silk fibroin (SF). Meanwhile, the effects of the mass radio of PLGA to SF on the properties of the electrospun monolayer nanofiber membrane was further investigated. The results of the electrospun monolayer PLGA-SF nanofiber membrane with mass radio of 2:1 displayed significant improvement in hydrophilicity as well as mechanical properties compared to the other mass radio of nanofibers membranes. Moreover, drug release studies revealed that nanofiber membrane with multilayer structure was able to promote a much more sustained release of ASA in comparison with monolayer PLGA-SF nanofibers membranes. More remarkable, the nanofiber membrane with multilayer structure presented good biocompatibility. Overall, these results demonstrate the potential of using PLGA-SF nanofibers with multilayer structure as a scaffold for drug-controlled release.