Controlled Release Properties Research Articles

Effects of emulsion concentration on the physicochemical properties of wheat bran arabinoxylan-soy protein isolate emulsion-filled gels used as β-carotene carriers

The application of natural polymers in emulsion-filled gels is an effective way to enhance the protective and controlled release properties of bioactive compounds. In this study, wheat bran arabinoxylan–soy protein isolate (WBAX-SPI) emulsion-filled gels were formed by embedding a WBAX emulsion containing 10 mL/100 mL soybean oil in a dispersion of WBAX and SPI polymer followed by gelation. The physicochemical properties of the emulsion-filled gels with different emulsion concentrations (9, 12, 15, 18, and 21 g/100 g) were evaluated. The WBAX-SPI emulsion-filled gels were self-supported gels with high water holding capacities (98 ± 0.5 g/100 g). Texture profile analysis showed that a highly integrated gel network was formed at the emulsion concentration of 15 g/100 g. Rheological measurements showed that the emulsion acted as an active filler in the WBAX-SPI emulsion-filled gels, leading to different rheological properties compared to the WBAX-SPI hydrogels. Confocal laser scanning microscopy observations indicated that the structure of the WBAX-SPI emulsion-filled gels was affected by the emulsion concentration. In vitro simulated digestion demonstrated that the WBAX-SPI emulsion-filled gels had better sustained release performance compared to the WBAX or SPI emulsion-filled gels.

Fabrication of cumin seed oil loaded gliadin-ethyl cellulose nanofibers reinforced with adipic acid for food packaging application

In this study, the water-insoluble cumin seed oil (CSO) loaded gliadin (GN)-nanofibers (NFs) mat was prepared in the presence of ethyl cellulose (EC) and adipic acid (AD) using electrospinning method. The NFs were prepared with mixing 30 % w/v of GN and 15 %w/v of EC at the ratio of 80:20 v/v and 5%w/v of AD were selected as optimum formulation based on electrospinning efficiency and SEM images. In the presence of EC, the spinnability of GN fibers improved. Moreover, in the presence of AD the fibers diameters decreased to 50 % (250 ± 14 nm), and uniformity enhanced in all formulations. AD acted as hydrogen bond cross-linker between mixed biopolymers that led to increase in the viscosity of the polymer solutions. The selected formulation was loaded with the CSO based on 10 %w/v of polymers. Thermal stability of the GN fibers was improved in the presence of EC and AD based on DSC results. The FTIR results confirmed the hydrogen bond crosslinking between polymers and AD. Based on antioxidant activities results, the prepared NFs successfully retarded the release of CSO. CSO loaded NFs showed the strong antibacterial and antifungal activity against Escherichia coli, Staphylococcus aureus, and Aspergillus flavus. NFs had no significant toxicity on the viability of normal human umbilical vein endothelial cell (HUVEC). The results of the current study indicated that the prepared NFs mat may have a great potential for using in active food packaging due to its sustained control release properties for loaded antimicrobial and antioxidant active agent.

Central Composite Design for Formulation and Optimization of Solid Lipid Nanoparticles to Enhance Oral Bioavailability of Acyclovir.

Treatment of herpes simplex infection requires high and frequent doses of oral acyclovir to attain its maximum therapeutic effect. The current therapeutic regimen of acyclovir is known to cause unwarranted dose-related adverse effects, including acute kidney injury. For this reason, a suitable delivery system for acyclovir was developed to improve the pharmacokinetic limitations and ultimately administer the drug at a lower dose and/or less frequently. In this study, solid lipid nanoparticles were designed to improve the oral bioavailability of acyclovir. The central composite design was applied to investigate the influence of the materials on the physicochemical properties of the solid lipid nanoparticles, and the optimized formulation was further characterized. Solid lipid nanoparticles formulated from Compritol 888 ATO resulted in a particle size of 108.67 ± 1.03 nm with an entrapment efficiency of 91.05 ± 0.75%. The analyses showed that the optimum combination of surfactant and solid lipid produced solid lipid nanoparticles of good quality with controlled release property and was stable at refrigerated and room temperature for at least 3 months. A five-fold increase in oral bioavailability of acyclovir-loaded solid lipid nanoparticles was observed in rats compared to commercial acyclovir suspension. This study has presented promising results that solid lipid nanoparticles could potentially be used as an oral drug delivery vehicle for acyclovir due to their excellent properties.

Development of biodegradable thin films for efficient, specific and controlled delivery of capecitabine

Cancer is the leading cause of death worldwide. Capecitabine (CP) shows severe side effects because of early metabolism in stomach that affects the normal cells and organs, particularly liver and stomach. In this scope, we report the biocompatible, nontoxic polymeric thin films loaded with anti-cancer drug, CP for target specific, sublingual delivery of CP. Chitosan (CS) and polyvinyl alcohol (PVA) were used as biodegradable polymers alongwith glutaraldehyde (GLA) cross linker. CP-loaded thin films (TFCP1–TFCP5) were fabricated by solvent casting method. The results of Fourier transform infrared spectroscopy confirmed the presence of CP and polymers (CS and PVA) with GLA which binds through hydrogen bonding, and compatibility of drug with different excipients. Thermogravemetric analysis showed that the thin films are highly stable while differential scanning calorimeter thermograms confirmed the complete miscibility/entrapment of CP within PVA/CS thin film matrix. X-ray diffraction patterns revealed the molecular ineractions between CP and polymer matrix. High degree of swelling index of thin films at pH 7.4 was observed in comparison to pH 5.5. CP release studies in acetate (pH 5.5) and phosphate buffer (pH 7.4) showed that the thin films swell and result in drug diffusion faster in phosphate buffer through diffusion governed by Higuchi’s model. Cytotoxicity results displayed that CPTFs killed MCF-7 and T47D (human breast adenocarcinoma) cells more effectively as compared to CP alone. The results of adhesion assay also showed that the PVA and CS both are safe and biocompatible. TFCP1 and TFCP3 thin films efficiently induced the apoptosis as compared to CP alone. The improved ability of TFCP1 and TFCP3 to induce cytotoxicity in MCF-7 cells reflects the potential of these thin films for targeted drug delivery. The CPTFs were stable for 4 months at 4 °C/60% ± 2%RH and 25 °C/70% ± 2%RH. In conclusion, the thin film formulations showed target specific controlled and burst release properties and thus could prove to be effective for human breast cancer treatment.

Engineering Natural Pollen Grains as Multifunctional 3D Printing Materials

AbstractThe development of multifunctional 3D printing materials from sustainable natural resources is a high priority in additive manufacturing. Using an eco‐friendly method to transform hard pollen grains into stimulus‐responsive microgel particles, we engineered a pollen‐derived microgel suspension that can serve as a functional reinforcement for composite hydrogel inks and as a supporting matrix for versatile freeform 3D printing systems. The pollen microgel particles enabled the printing of composite inks and improved the mechanical and physiological stabilities of alginate and hyaluronic acid hydrogel scaffolds for 3D cell culture applications. Moreover, the particles endowed the inks with stimulus‐responsive controlled release properties. The suitability of the pollen microgel suspension as a supporting matrix for freeform 3D printing of alginate and silicone rubber inks was demonstrated and optimized by tuning the rheological properties of the microgel. Compared with other classes of natural materials, pollen grains have several compelling features, including natural abundance, renewability, affordability, processing ease, monodispersity, and tunable rheological features, which make them attractive candidates to engineer advanced materials for 3D printing applications.

Milk protein inspired multifunctional magnetic carrier targeting progesterone receptors: Improved anticancer potential of soybean-derived genistein against breast and ovarian cancers

Plant-based bioactive compounds are actively researched as bioinspired green cytotoxic agents replacing synthetic drugs. The present study reports application of milk protein (casein) based pH and magnetic field responsive carrier functionalized with progesterone for the cancer site specific delivery of bioinspired cytotoxic agent genistein. Casein on hybridization with superparamagnetic calcium ferrite exhibited enhanced stability, cytocompatibility, high surface area for drug encapsulation and magnetically controllable release properties. The dietary isoflavonoid genistein was derived from soybeans using microwave-assisted method and the drug-encapsulated carrier was conjugated with progesterone to target the receptors expressed on breast or ovarian cancer cells. The drug loading in carrier was optimized to 88.67%, with a surface charge of −32.4 ± 1.6 mV and particle size 145 ± 3.7 nm. The encapsulated drug was actively released from the carrier in response to the acidic pH mimicking cancer environment (~5.4), whereas it was highly stable with negligible release at normal bodily pH (~7.4). Cell metabolic activity studies on fibroblast cells validated the non-toxicity of the system. From the selective cellular uptake and targeted chemo-hormonal effect supported by the nanocarrier, the genistein drug exhibited excellent therapeutic effect on ovarian (SKOV-3) and breast (MDA-MB-231) cancer cells, with drastic decrease in IC50 values (38.42 to 0.27 and 34.78 to 0.52 (μg/ml), respectively). The obtained results support the potential of the bioinspired, nanohybrid drug delivery system for targeted anti-cancer therapy.

Hyaluronic acid-modified manganese dioxide-enveloped hollow copper sulfide nanoparticles as a multifunctional system for the co-delivery of chemotherapeutic drugs and photosensitizers for efficient synergistic antitumor treatments

This paper presents the design of a new type of intelligent and versatile all-in-one therapeutic nanoplatform for the co-delivery of chemotherapeutic drugs and photosensitizers to facilitate multimodal antitumor treatment; the system is based on hyaluronic acid (HA)-modified manganese dioxide (MnO2)-enveloped hollow porous copper sulfide (CuS) nanoparticles (CuS@MnO2/HA NPs). In this system, a CuS inner shell allows for the co-loading of doxorubicin (DOX) and indocyanine green (ICG) and induces photothermal effects, and a biodegradable MnO2 external shell affords on-demand tumor microenvironment (TME)-triggered release and catalase- andFenton-like activities. Moreover, the HA modification endows the system with a CD44 receptor-mediated tumor-targeting property. The formulated DOX and ICG co-loaded CuS@MnO2/HA (DOX/ICG-CuS@MnO2/HA) NPs were found to exhibit excellent photothermal performance both in vitro and in vivo. In addition, DOX/ICG-CuS@MnO2/HA NPs were found to display both TME and near-infrared (NIR)-responsive controlled release properties. The NPs also have a superior reactive oxygen species (ROS) generation capacity due to the combination of enhanced ICG-induced singlet oxygen and CuS@MnO2-mediated hydroxyl radicals. The cellular uptake, fluorescence imaging property, cytotoxicity, and thermal imaging of these NPs were also evaluated. In tumor-bearing mice, the DOX/ICG-CuS@MnO2/HA NPs displayeda superior antitumor efficacy (2.57-fold) as compared with free DOX. Therefore, the developed DOX/ICG-CuS@MnO2/HA NPs have a great potential for use as an all-in-one nanotherapeutic agent for the efficient and precise induction of chemo/photothermal/photodynamic/chemodynamic therapy with superior antitumor efficacy and fewer side effects.

PH-Responsive Capsule Polymer Particles Prepared by Interfacial Photo-Cross-Linking: Effect of the Alkyl Chain Length of the pH-Responsive Monomer.

pH-responsive capsule particles have immense potential for use in various advanced fields, such as microreactors and drug delivery. Moreover, the interfacial photo-cross-linking of spherical polymer particles is a promising strategy to create various functional capsule particles. In this study, pH-responsive capsule polymer particles were prepared by interfacial photo-cross-linking with photo-reactive polymers possessing different pH-responsive monomer units of different alkyl chain lengths, namely, 2-dimethylaminoethyl methacrylate, 2-diethylaminoethyl methacrylate, and 2-diisopropylaminoethyl methacrylate. Using these different pH-responsive monomers, regulation of the controlled release properties of pH-responsive capsule particles was achieved. All capsule particles prepared from these three different polymers released encapsulated molecules under acidic conditions; however, more acidic conditions were necessary for releasing encapsulated molecules with the increasing alkyl chain length. The afforded results indicated that pH-responsive monomers of different alkyl chain lengths could be successfully employed to regulate the pH-responsive controlled release property of the capsule particles prepared by interfacial photo-cross-linking.

Recent advances in polymer shell oily-core nanocapsules for drug-delivery applications.

Polymeric nanocapsules are vesicular drug-delivery systems composed of an inner oily reservoir surrounded by polymeric membranes. Nanocapsules have various advantages over other nanovesicular systems such as providing controlled drug release properties. We discuss the recent advances in polymeric shell oily-core nanocapsules, illustrating the different types of polymers used and their implementation. Nanocapsules can be utilized for many purposes, especially encapsulation of highly lipophilic drugs. They have been shown to have variable applications, especially in cancer therapy, due to the ability of the polymeric shell to direct the loaded drugs to their target sites, as well as their high internalization efficacy. Those productive applications guaranteed their high potential as drug-delivery systems. However, their clinical development is still in an early stage.

Benzimidazole loaded β-cyclodextrin as a novel anti-corrosion system; coupled experimental/computational assessments

HypothesisSilane (sol–gel)-based coatings have been introduced as an eco-friendly system for reducing the metals' corrosion in NaCl solutions. However, due to the lack of active protection property for this type of coatings, their modification is totally recommended for achieving durable protection properties. The present study introduces Beta-cyclodextrin (β-CD) as a novel/effective organic nano-container for Benzimidazole (BM) encapsulation to obtain reliable active protection property via a controlled-release property. ExperimentsThe chemical structure of the β-CD-BM macromolecule was explored by Fourier-transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD), and Ultraviolet–visible spectroscopy (UV–Vis). Besides, the Electrochemical Impedance Spectroscopy (EIS) and polarization (potentiodynamic) tests were carried out for investigating the inhibition impacts of the constructed containers. The exposed and unexposed samples' surfaces were analyzed by Field Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive Spectroscopy (EDS)/mapping, and Grazing incidence X-ray diffraction (GIXRD) experiments. Also, the EIS test was conducted over the Silane-based composite film (SCF) for analyzing the anti-corrosion performance of the constructed composites. FindingsThe EIS achievements demonstrated that by the addition of β-CD-BM complexes to the saline solution, the mild steel corrosion was mitigated by about 84%. The EIS results also displayed that the total resistance of the modified composite was enhanced from 5540 Ω.cm2 to 10967 Ω.cm2 and the intact coating provided a total resistance of 80254 Ω.cm2. The dispersion-corrected Density Functional Theory (DFT)-D explorations ascertained the inclusion capacity of benzimidazole inside the β-CD. The Monte Carlo/Molecular Dynamics (MC/MD) calculations strongly affirmed the adsorption of BM and β-CD-BM over the substrate.

Fabrication and evaluation of Lambda-Cyhalothrin nanosuspoemulsion with pH- and temperature-responsive based on polyethylene wax as carrier

Using polyethylene wax (PW) as the coating matrix, the lambda-cyhalothrin-PW nanosuspoemulsion (LC-PW) with a particle size of 80-150nm was prepared through high-speed stirring, hot melt emulsification and ultrasonic dispersion. The formulation and composition of the LC-PW were optimized, the morphology of the LC-PW was analyzed by dynamic light scattering (DLS) and TEM, and the structure of the LC-PW was characterized by UV and IR. The anti-photolysis test showed that LC-PW had a good anti-photolysis performance. Furthermore, LC-PW could sustainably release Lambda-cyhalothrin, which was pH- and temperature dependent. The insecticidal activity analysis in the greenhouse indicated that the toxic strength between LC-PW and LC-SC (lambda-cyhalothrin-suspension concentrate) to Mythimna separata was similar within the same concentration ranges tested, but the insecticidal duration of LC-PW was significantly longer than LC-SC. Thus, the new type of LC-PW with the properties of anti-photolysis and controlled release is suitable for application in the field as a better insecticide.

MiR-197 Inhibitor Loaded AbCD133@MSNs@GNR Affects the Development of Prostate Cancer Through Targeting ITGAV

Prostate cancer is one of the most severe male malignant tumors, which ranks second in mortality rate among all tumors. Traditional methods of treatment for prostate cancer produce obvious side effects and a high recurrence rate. Cancer stem cells are considered to be a group of cells that determine the proliferation, metastasis, and drug resistance of tumor. Prostate cancer therapy based on microRNAs and prostate cancer stem cells (PCSCs) has been a research hot spot in this field. Previous studies have reported that miR-197 plays an important role in the occurrence and development of prostate cancer, but the molecular mechanism of miR-197 on the development of prostate cancer has not been reported yet. In this study, we verified that miR-197 is significantly overexpressed in prostate cancer tissues and prostate cancer cells. Then, we verified that miR-197 expression affects the proliferation, invasion, and metastasis of prostate cancer cells by regulating integrin subunit alpha V (ITGAV) expression through STAT5 pathway, and the results indicated that the miR-197 inhibitor can be a prostate cancer suppressor. Then we synthesized the AbCD133@GNR@MSNs@miR-197 inhibitor drug carrier, in which 35.42 μg of the miR-197 inhibitor could be loaded in 1 mg of AbCD133@GNR@MSNs. The AbCD133@GNR@MSNs@miR-197 inhibitor demonstrated good photothermal properties and photothermal controlled-release properties. The modified CD133 antibodies on the surface of the nano drug carrier helped more drug carriers to enter the PCSCs. The pharmacodynamic effects of the AbCD133@GNR@MSNs@miR-197 inhibitor on PCSCs in vivo and in vitro were studied under near-infrared radiation. The results showed that the AbCD133@GNR@MSNs@miR-197 inhibitor prepared in this study could not only significantly suppress the development of PCSCs through ITGAV/STAT5 pathway but also significantly suppress the growth of PCSC solid tumors. In short, our study verified that miR-197 regulates the development of PCSCs through STAT5 pathway by targeting ITGAV, and the AbCD133@MSNs@GNR@miR-197 inhibitor could be a potential suppressor used in prostate cancer treatment. In short, our study found that miR-197 affected the development of prostate cancer by regulating ITGAV. The AbCD133@GNR@MSNs@miR-197 inhibitor prepared in this study could suppress the development and growth of PCSCs in vitro and in solid tumors not only by targeting the ITGAV but also through photothermal therapy. Our study not only provides a theoretical basis for the clinical treatment of prostate cancer but also provides a research scheme of drug loading and microRNA-based photothermal controlled therapy for prostate cancer.

Mesoporous CeO2 containers in water-borne epoxy coatings for dual active corrosion protection of mild steel

In this work, a new type of cerium oxide particles with a graded mesoporous structure (Hierarchically meso-mesoporous cerium oxide, HMCe) was prepared as both inhibitor and carrier for loading 2-MBI (2-mercaptobenzimidazole) inhibitor, which was encapsulated by Eudragit E100 (EE100, a kind of amino methacrylate copolymer) to construct smart containers with pH controlled-release properties. The smart containers were added to a water-borne epoxy coating to develop active anti-corrosion coating on mild steel. The corrosion inhibition effect of 2-MBI and mesoporous cerium oxide particles was evaluated. Furthermore, the release of 2-MBI from the smart containers in response to acidic corrosion solution was also investigated using UV–vis spectroscopy. Electrochemical impedance spectroscopy (EIS) and salt spray tests were employed to evaluate the barrier properties and the active anti-corrosion performance of the coatings. The results showed that coating with newly designed smart containers has better anti-corrosion performance than coating with cerium oxide particles or 2-MBI alone. This work provides a new way to fabricate containers and actively protective coatings.

Near-Infrared Light-Regulated Drug-Food Homologous Bioactive Molecules and Photothermal Collaborative Precise Antibacterial Therapy Nanoplatform with Controlled Release Property.

Herein, a collaborative precise antibacterial wound healing therapy nanoplatform integrating drug-food homologous bioactive molecule (cinnamaldehyde, CA) with photothermal therapy (PTT) is presented. Copper-gallic acids-cinnamaldehyde-polydopamine nanorods (Cu-GA-CA-PDA NRs) with near-infrared light (NIR)-controlled CA release property are fabricated, which also integrate CA and photothermal synergistic sterilization, as well as antioxidant, anti-inflammatory, and anti-infection capacities. The characteristics of NIR-mediated CA release and photothermal response of Cu-GA-CA-PDA NRs support their excellent sterilization performance in vitro/in vivo. In addition, under the guidance of NIR, Cu-GA-CA-PDA NRs can hinder the formation of inflammatory cells, reduce oxidative stress damage, accelerate the regeneration of skin tissues in S. aureus-infected wound sites, and achieve the goal of promoting wound healing. Therefore, NIR-mediated Cu-GA-CA-PDA NRs with multifunctional biological activities provide a highly competitive strategy for curing bacteria-infected wounds.

The effect of cross-linker type on structural, antimicrobial and controlled release properties of fish gelatin-chitosan composite films incorporated with ε-poly-l-lysine

In this study, active antibacterial cross-linked composite films were prepared through incorporating ε-poly-l-lysine (ε-PLL) into Siberian sturgeon gelatin-chitosan mixture. Cross-linking was performed by Glutaraldehyde (G) and/or Cinnamaldehyde (C). The antimicrobial, ε-PLL release, mechanical and morphological properties were then investigated. The addition of G to the biopolymer mixture significantly resulted in lower water vapor permeability, enhanced mechanical strength, lower moisture content, and water solubility. The FTIR spectra indicated the formation of imine bonds in the composite film network. The microstructure of composite films was affected by the cross-linking agent. The films cross-linked by G and C showed smooth and rough surfaces, respectively. C induced very small pores in the cross-section of the composite film. The composite films incorporated with ε-PLL revealed higher and steady-state in vitro antimicrobial properties against food spoilage bacteria. A higher release of ε-PLL and hence higher antibacterial activity was measured in the matrices cross-linked by C than those cross-linked by G. The results showed that the ε-PLL-fortified fish gelatin/chitosan composite films can be considered as a food-packaging material. G and C, as cross-linkers, can improve the structural and antimicrobial properties of this composite film.

Preparation and characterization of fluorometholone molecular imprinted soft contact lenses as ocular controlled drug delivery systems

The molecular imprinted (MIP) and non-imprinted (NIP) lenses were synthesized in presence and absence of Fluorometholone (FML) as the template molecule. Hydroxyethyl methacrylate (HEMA), as a backbone monomer, methacrylic acid (MAA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as a cross-linker monomer were applied to preparing soft contact lenses with different FML: MAA molar ratios. The lenses were characterized by determination of swelling and binding properties in water. Transparency and differential scanning calorimetry (DSC) properties of Drug-loaded and drug-free MIP lenses were also studied. Their loading and release properties were also studied using Korsmeyer-Peppas equation in Normal Saline (0.9% NaCl) and Artificial Tears media. There was no significant difference in swelling percentage of MIP and NIP lenses (p-value>0.05). No endothermic peak was seen at the melting point of FML in thermograms of drug-free and drug-loaded MIP lenses. It was found that all MIP lenses had higher binding affinity to FML in comparison with NIP (p-value<0.05). According to drug release data, Korsmeyer-Peppas equation shows non-Fickian diffusion pattern from hydrogel in 0.9% Normal Saline and Artificial Tears media and MIP1:12 had superior binding and release properties. The results of the present work indicated that molecular imprinting technique had a significant effect on improving loading capacity and sustaining drug release from hydrogels. According to our data MIP1:12 had more FML loading capacity and superior controlled release properties compared to other polymers and can be evaluated, in future studies, for making FML imprinted soft contact lenses.

Synthesis and Characterisation of Zinc Layered Hydroxide Intercalated with 2-Methyl-4- Chlorophenoxyacetic Acid and its Controlled Release Application

2-methyl-4-chlorophenoxyacetic acid (MCPA) is herbicide in group of phenoxyherbicides. It has been widely used in agriculture industry to control the weeds population especially thistle and dock. The toxicity of MCPA may impact the environment and harmful for living organisms especially human and aquatic life. This research aimed to intercalate MCPA herbicide with zinc layered hydroxide (ZLH) to form a composites (ZMCPA) and its controlled release properties. In this study, ZMCPA was prepared as an advanced delivery system by ion exchange method and further by hydrothermal treatment. The intercalations of zinc oxide were done with various MCPA concentration of 0.1 M, 0.3 M, 0.5 M, 0.7 M and 0.9 M. Intercalation performances were detected using powder X- ray diffraction (PXRD) and supported by Fourier Transform infrared spectroscopy (FTIR). The study for porosity of the composite was performed by BET analyzer. Among all of these concentrations, 0.5M represented the successful intercalation due to the presence of four sharp and intense harmonic peaks at 2θ with basal spacing of 24.6 Å, 12 Å, 8 Å and 6 Å, respectively. Herbicides release study was conducted in three salt solution, sodium chloride, sodium carbonate and sodium phosphate. Sustain release of MCPA was faster in sodium phosphate solution by 85%. This controlled release study was determined by UV-Vis spectrometry.

A Novel Approaches - Gastroretentive Microballoons Drug Delivery System

Due to its potential to stay in the gastric region for a longer period of time, the gastro-retentive is one of the most promising oral drug delivery systems. This increases the solubility of the drug, which improves bioavailability and reduces drug waste. To achieve the gastro-retentive property, numerous methods have been proposed. Microballoons are the most common form among them. Microballoons (hollow microspheres) have the ability to be a viable option for gastric retention. The microballoons drug delivery system is based on a non-effervescent system that comprises hollow spherical particles with no center and a size of less than 200 micrometres. The microballoons drug delivery system has been shown to be more effective in regulating the rate of release of drugs with site-specific absorption. The floating Microballoons demonstrated gastro-retentive mediated release delivery with effective methods for increasing bioavailability, and they could be a promising solution for gastric retention. Optimized hollow microspheres could play a key role in novel drug delivery, especially in secure, targeted, and efficient in vivo delivery. They may be a promising approach for gastric retention, which would minimize variability in plasma drug concentrations. The review presents an insight in to recent advance methods of formulation, evaluation, polymers used in microballoons, applications of microballoons as gastroretentive drug delivery system which provide controlled release properties.

Fabrication, characterization and controlled release properties of yak casein cold-set gels

The casein cold-set gel was prepared from yak qula and the gel characterizations and embedding features were investigated by means of rheological property analysises, texture profile analysises, laser confocal microscopic observation, and in vitro simulated digestion experiment. The results showed that the hardness and elasticity of the gel were increased with the concentration of glucono-δ-lactone (GDL) and NaCl. Better water holding capacity (WHC) was observed in the gel with a lower concentration of GDL (1%) and NaCl (0.2M) than that with high concentration of GDL (2%) and NaCl (0.2M, 0.4M). GDL significantly affected the energy storage modulus (G’) and loss modulus (G”) values. Confocal laser scanning microscopy (CLSM) observations and fractal analysis further demonstrated that electrostatic interaction was the major force in the gel formation, which was characterized by reactive limited polymerization. The in vitro experiment on casein cold-set gel encapsulation of bioactive ingredient (Que) showed favorable encapsulation and controlled-release performance. In conclusion, Yak casein (YCN) cold-set gel would be an useful matrix for the application of encapsulation, protection, delivery and controlled-release of some bioactive components.

Shape memory polyacrylamide/gelatin hydrogel with controllable mechanical and drug release properties potential for wound dressing application

In this work, various shape memory polyacrylamide/gelatin (PAM-Gels) hydrogels with interpenetrating double networks were synthesized via a facile one-pot method. Taking advantage of the thermal reversible property of physical gelatin network and the constant of chemical crosslinking polyacrylamide network, the prepared PAM-Gels hydrogels showed shape memory function under warm water. Moreover, the shape memory, mechanical, drug release, and swelling properties of the prepared PAM-Gels hydrogels could be tuned by altering the gelatin component content. Notably, the PAM-Gel5 hydrogel containing 5% w/v of gelatin exhibited the most effective enhancements in physicochemical properties, and the highest shape fixity and shape recovery rate were 78.2% and 93.5%, respectively. Meanwhile, it could retain the integrity of its shape even with high water uptake. More importantly, the PAM-Gel5 hydrogel possessed well balanced mechanical properties (e.g. tensile strength was 0.57 MPa and elongation at break was 1556% in tensile test; compression stress was 0.06 MPa and Young's modulus was 0.38 MPa in compression test) among the as-prepared PAM-Gels hydrogels, due to its uniform pore size distribution and smaller pore size. Furthermore, the drug release experiment revealed that the PAM-Gel5 hydrogel showed sustained release characteristics, and the majority of loaded model drug could be released within 24 h under physiological conditions. Additionally, cytotoxicity test suggested the representative PAM-Gel5 hydrogel exhibited good in vitro cytocompatibility. This work provides a viable avenue for developing bio-compatible shape memory hydrogel with acceptable mechanical and drug release properties applied as wound dressing.