Release System Research Articles

Spatiotemporally Controlled Release of Etamsylate from Bioinspired Peptide-Functionalized Nanoparticles Arrests Bleeding Rapidly and Improves Clot Stability in a Rabbit Internal Hemorrhage Model.

Achieving rapid clotting and clot stability are important unmet goals of clinical management of noncompressible hemorrhage. This study reports the development of a spatiotemporally controlled release system of an antihemorrhagic drug, etamsylate, in the management of internal hemorrhage. Gly-Arg-Gly-Asp-Ser (GRGDS) peptide-functionalized chitosan nanoparticles, with high affinity to bind with the GPIIa/IIIb receptor of activated platelets, were loaded with the drug etamsylate (etamsylate-loaded GRGDS peptide-functionalized chitosan nanoparticles; EGCSNP). Peptide conjugation was confirmed by LCMS, and the delivery system was characterized by DLS, SEM, XRD, and FTIR. In vitro study exhibited 90% drug release till 48 h fitting into the Weibull model. Plasma recalcification time and prothrombin time tests of GRGDS-functionalized nanoparticles proved that clot formation was 1.5 times faster than nonfunctionalized chitosan nanoparticles. The whole blood clotting time was increased by 2.5 times over clot formed under nonfunctionalized chitosan nanoparticles. Furthermore, the application of rheometric analysis revealed a 1.2 times stiffer clot over chitosan nanoparticles. In an in vivo liver laceration rabbit model, EGCSNP spatially localized at the internal injury site within 5 min of intravenous administration, and no rebleeding was recorded up to 3 h. The animals survived for 3 weeks after the injury, indicating the strong potential of the system for the management of noncompressible hemorrhage.

Polystyrene Sulfonate Resin as an Ophthalmic Carrier for Enhanced Bioavailability of Ligustrazine Phosphate Controlled Release System

Topical ocular sustained-release drug delivery systems represent an effective strategy for the treatment of ocular diseases, for which a suitable carrier has yet to be sufficiently developed. Herein, an eye-compatible sodium polystyrene sulfonate resin (SPSR) was synthesized with a uniform particle size of about 3 μm. Ligustrazine phosphate (LP) was adsorbed to SPSR by cation exchange to form LP@SPSR. LP@SPSR suspension eye drops were further developed using the combination of Carbopol 934P and xanthan gum as suspending agents. The LP@SPSR suspension showed a sustained release in vitro, which was consistent with the observed porcine corneal penetration ex vivo. Pharmacokinetics in tear fluid of rabits indicated that LP@SPSR suspension led to prolonged ocular retention of LP and a 2-fold improved the area under the drug concentration-time curve (AUC0-t). Pharmacokinetics in the aqueous humor of rabbits showed 2.8-fold enhancement in the AUC0-t compared to LP solution. The LP@SPSR suspension exhibited no cytotoxicity to human corneal epithelial cells, nor irritation was observed in rabbit eyes. Thus, the LP@SPSR suspension has been validated as a safe and sustained release system leading to enhanced ophthalmic bioavailability for treating ocular diseases.

Design of Thermosensitive Niosomes by Eutectic Mixture of Natural Fatty Acids.

In the current study, a smart release system responsive to temperature was developed to improve the efficiency of tetracycline (TC) in antibacterial therapy. The nanovesicles designed consist of a non-ionic surfactant, SPAN60, cholesterol and a phase change material (PCM) as a thermoresponsive gating material. Niosomes were prepared using an increasing amount of PCM and characterized in terms of size, zeta potential, colloidal stability and thermoresponsive properties. The vesicles that developed were homogenous in size, had good biocompatibility and stability for up to 3 months and demonstrated thermoresponsive behavior. A low drug leakage was observed at 37 °C, while a rapid release occurred at 42 °C, due to the faster diffusion rate of the drug trough the melted PCM. This controllable drug release capacity allows us to avoid premature drug release, minimizing unwanted and toxic effects and ensuring a long retention time in the nanodevice so that it reaches the infected sites. In addition, TC-loaded niosomes were screened to investigate their antibacterial activity against various Gram-positive and Gram-negative bacteria by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. An interesting temperature-dependent antibacterial activity was observed against some bacterial strains: the niosomes activity against S. epidermis, for example, was improved by the temperature increase, as suggested by a reduction in MIC values from 112.81 to 14.10 μM observed at 37 and 42 °C, respectively. Taken together, the thermoresponsive platform developed allows us to use lower antibiotic amounts while ensuring therapeutic efficacy and, so, will advance the development of a novel antibacterial agent in clinical practice.

Release behavior of antifouling materials based on intercalated layered double hydroxides

Improving the utilization rate of environmentally friendly antifouling agents is highly important for reducing the economic costs of ship operations and protecting the marine environment. In this work, a new method for preparing a multistage controlled release material of an environmentally friendly antifouling agent, which first incorporates 2-(p-chlorophenyl)-3-cyano-4-bromo-5-trifluoromethyl pyrrole (Econea) into carboxyl-modified β-cyclodextrin (Econea@CMCD) followed by intercalation into Mg2Al layered double hydroxides (Mg2Al-Econea@CMCD-LDH), was reported. Powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) confirmed the incorporation of Econea@CMCD into the galleries of Mg2Al-LDH. Release tests conducted in 3.5 % NaCl solution demonstrated an initial burst release, followed by a slower release rate of Econea (12.3 µg/cm2·d) compared to that of the pristine Econea coating, indicating favorable controlled release behavior. Adhesion experiments using diatoms and mussels showed that Mg2Al-Econea@CMCD-LDH effectively inhibited the adhesion of typical fouling organisms. Hence, this study presents a practical approach for constructing a controlled release system that involves intercalating neutral and insoluble antifouling agents into LDH interlayers, effectively reducing the waste of antifouling agents and extending the service life of antifouling coatings.

Enhanced curcumin solubility in epichlorohydrin engineered β-Cyclodextrin copolymer for gastric maladies

The present work relates to a β-cyclodextrin based drug delivery system with epichlorohydrin as cross-linking agent, with higher binding efficiency of the drug curcumin and enhanced solubility of the curcumin in complex form when simulated in gastric fluid and increased sustained release of curcumin from complex for 2 h to act in gastric region. Although cross-linking with epichlorohydrin (EPC) is a process studied long time ago, however its use as a gastric solubility enhancer for curcumin has been studied for the first time. The synthesized polymer was well characterized by FT-IR, SEM, XRD, TGA and particle size analysis. The polymer enhanced the water solubility of curcumin by ∼ 800–850 times and the gastric solubility was increased by ∼ 1400–1500 times and acted as a sustained release system as verified by the pepsin inhibition studies which makes it a potential drug carrier for gastric specific drug targeting that can be a promising treatment for gastritis and gastric ulcers.

Synthesis of double network nanohydrogel and its performance in release of doxorubicin

The synthesis, properties, and performance of a controlled drug (doxorubicin, DOX) release system based on a double-network nanohydrogel (DNN) obtained from poly(acrylic acid) grafted onto sodium alginate (S-ALG) are described. The drug release behavior of DNNs was studied under different pH and temperature conditions. The DNNs were characterized by ultraviolet-visible (UV) spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), and thermogravimetric analysis (TGA). DNN was confirmed to be suitable for use in controlled drug delivery systems.

Development of a local controlled release system for therapeutic proteins in the treatment of skeletal muscle injuries and diseases

The present study aims to develop and characterize a controlled-release delivery system for protein therapeutics in skeletal muscle regeneration following an acute injury. The therapeutic protein, a membrane-GPI anchored protein called Cripto, was immobilized in an injectable hydrogel delivery vehicle for local administration and sustained release. The hydrogel was made of poly(ethylene glycol)-fibrinogen (PEG-Fibrinogen, PF), in the form of injectable microspheres. The PF microspheres exhibited a spherical morphology with an average diameter of approximately 100 micrometers, and the Cripto protein was uniformly entrapped within them. The release rate of Cripto from the PF microspheres was controlled by tuning the crosslinking density of the hydrogel, which was varied by changing the concentration of poly(ethylene glycol) diacrylate (PEG-DA) crosslinker. In vitro experiments confirmed a sustained-release profile of Cripto from the PF microspheres for up to 27 days. The released Cripto was biologically active and promoted the in vitro proliferation of mouse myoblasts. The therapeutic effect of PF-mediated delivery of Cripto in vivo was tested in a cardiotoxin (CTX)-induced muscle injury model in mice. The Cripto caused an increase in the in vivo expression of the myogenic markers Pax7, the differentiation makers eMHC and Desmin, higher numbers of centro-nucleated myofibers and greater areas of regenerated muscle tissue. Collectively, these results establish the PF microspheres as a potential delivery system for the localized, sustained release of therapeutic proteins toward the accelerated repair of damaged muscle tissue following acute injuries.

Review Article About Gel Polymers and Their Applications

One of the important applications of hydrogels is agricultural applications, as there is a controlled release of nutrients from the hydrogel into the soil, which are fertilizers loaded on the hydrogel. A large part of the fertilizer added to the soil is lost through leaching, especially in highly porous soils, in chemical processes, heavy rains, etc. A number of different polysaccharides, such as chitosan, pectin and carboxymethyl cellulose have been used to prepare hydrogels as a fertilizer release system for soil revitalization. Many studies have been conducted in this field. For example, Agaba et.al indicated that moisture retention in a particular soil due to the hydrogel is necessary to create a forest. Planted Water affects soil properties such as aeration, temperature, nutrient transfer, water absorption and conversion, which affects plant growth. Dimitri et al investigated the applicability of cellulose-based hydrogels in three different formulations, i.e. crosslinked by carbodiimide, as a carrier for sustained and controlled release of water and as nutrients in arid and desert regions.

Intra-articular injection of modified citrus pectin and hyaluronate gel induces synergistic effects in treating osteoarthritis

We previously found that modified citrus pectin (MCP), an inhibitor of pro-inflammatory factor Galectin-3 (Gal-3), has significant anti-inflammatory and chondroprotective effects. In this study, a hyaluronate (HA) gel-based sustained release system of MCP (MCP-HA) was developed as an anti-inflammatory agent for chronic inflammation for osteoarthritis (OA) treatment. The MCP-HA gel was injected into the knee joint cavities of OA rabbit models induced by anterior cruciate ligament transection (ACLT) or modified Hulth method once a week for five weeks. We found that MCP-HA could improve the symptoms and signs of OA, protect articular cartilage from degeneration, suppress synovial inflammation, and therefore alleviate OA progression. Proteomic analysis of the synovial fluid obtained from the knee joints of OA rabbits revealed that MCP-HA synergistically regulated the levels of multiple inflammatory mediators and proteins involved in metabolic pathways. Taken together, our results demonstrate that the MCP-HA shows a synergistic effect of HA and MCP by modulating both inflammation and metabolic processes, thereby alleviating OA progression. The MCP-HA sustained release system has promising potential for long-term use in OA treatment.

Alginate/hyaluronic acid/gelatin ternary blended films as pH-sensitive drug carriers: In vitro ampicillin release and kinetic studies

Researchers continuously focused on the fabrication of innovative drug delivery systems to prevent microbial infections while minimizing systemic side effects. Among these, pH-sensitive antibiotic release systems based on bio-based materials have gained great attention due to their ability to precisely modulate drug kinetics and enhance therapeutic efficacy. Herein, pH-sensitive alginate/hyaluronic acid/gelatin ternary blended films were fabricated for the controlled release of ampicillin. Swelling capacity, hydrolytic degradation profile, pH reversibility and in vitro ampicillin release behavior of produced films were investigated in both simulated gastric (pH 1.2) and intestinal (pH 7.4) environments. The cumulative release amount of ampicillin at pH 1.2 (61.0 ± 1.07 mg drug/g polymer) was greater than that of at pH 7.4 (43.0 ± 1.05 mg drug/g polymer) proved that release behavior of ampicillin for produced films is pH-dependent. Based on the fitted release data, best fit was found as the first-order kinetic model with the highest R2 values of 0.966 and 0.962 for both pH conditions. According to Korsmeyer-Peppas model, drug release mechanism is also controlled by case II-transport. Furthermore, produced films demonstrated excellent cytocompatibility. All results revealed that obtained films could be a promising drug carrier to traditional targeting systems for site-specific, pH-sensitive ampicillin delivery in both gastric and intestine.

Dual pH and NIR-controlled release system for metal coating protection

Mesoporous materials are often utilized as nanocarriers to encapsulate corrosion inhibitors. However, the loading process is often complex, and the loading efficiency of corrosion inhibitors is unsatisfactory. In this research, we present a strategy for one-pot encapsulation of benzotriazole (BTA) in polypyrrole (PPy). The prepared composite material (PPy@BTA) can release corrosion inhibitors in response to acid and alkali stimulation and has the ability of near-infrared (NIR) photothermal response. Electrochemical impedance spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and wire beam electrode techniques were employed to confirm the self-healing property of the scratched coating embedded with PPy@BTA. Results indicated that the combination of NIR and pH-responsive self-healing effects endowed the composite coating with a long-term protection effect and repeatable self-healing behavior. This research broadens the scope of the use of PPy and provides new strategies for metal corrosion protection.

A dual UV light-trigged and pH-responsive release system based on functional ZIF-8

We developed zeolitic imidazolium framework-8 (ZIF-8) complexes loaded with cerium corrosion inhibitor and pH-jump reagent 2-nitrobenzaldehyde (ONBA), called ZIF-8/Ce@ONBA, for the intelligent control of metal corrosion by using a simple one-pot method. The pH-jump reagent can utilize ultraviolet (UV) light to induce the acidic degradation of ZIF-8 and achieve the controlled release of cerium inhibitor. The measurement results of the inductively coupled plasma mass spectrometry show that the release of cerium ions from the ZIF-8/Ce@ONBA reaches 42 mg/L after 9 h of UV irradiation. The release amount can reach 53 mg/L under a pH of 3 for 24 h. The results of electrochemical measurements and corrosion morphology observations also confirm that the fabricated ZIF-8/Ce@ONBA considerably suppresses the corrosion of aluminum alloy. Furthermore, these pH-responsive and UV-triggered properties endow the composite coating with a short-time self-healing ability and an excellent anticorrosion performance. These results underscore the potential of this composite to provide an efficient and intelligent delivery of corrosion inhibitors to metals for corrosion protection. This composite also presents an avenue for developing sustainable industrial corrosion protection.

To Formulate and Evaluate the Metformin Hydrochloride Floating Tablet

The aim of the research was to create a gastro retentive system for prolonged release of metformin HCl in the proximal part of the gastrointestinal tract (GIT) in the form of an oral floating tablet. Metformin HCl is an antidiabetic biguanide with poor bioavailability and an absorption window in the upper GIT. Floating tablets were prepared using a wet granulation method containing the natural polymers guar gum and kcarrageenan and the synthetic polymer HPMC K100 (HPMC) either alone or in combination. Sodium bicarbonate and citric acid were used as gas generators. Floating tablets were evaluated for weight variation, hardness and friability, drug content, swelling index, in vitro buoyancy and in vitro drug release. The formulation is optimized based on buoyancy, matrix integrity and in vitro drug release in simulated gastric fluid at pH 1.2. A formulation formulated with a combination of 6 wt. % k-carrageenan and 11 wt. % guar gum showed good gel strength, stable and continuous buoyancy for 12 hours, minimal buoyancy delay of 58 seconds, and good matrix integrity during dissolution period. The drug release of the optimized formulation followed the Korsmeyer- Peppas model and the mechanism was non-Fickian/divergent. PXRD and DSC studies showed partial amorphization of the drug. The mechanism of drug release appeared to be a diffusion mechanism. Stability studies have shown that the drug does not degrade when stored for 3 months at 40˚C.

Hard Gelatin Capsules with Alginate-Hypromellose Microparticles as a Multicompartment Drug Delivery System for Sustained Posaconazole Release.

Microparticles as a multicompartment drug delivery system are beneficial for poorly soluble drugs. Mucoadhesive polymers applied in microparticle technology prolong the contact of the drug with the mucosa surface enhancing drug bioavailability and extending drug activity. Sodium alginate (ALG) and hydroxypropyl methylcellulose (hypromellose, HPMC) are polymers of a natural or semi-synthetic origin, respectively. They are characterized by mucoadhesive properties and are applied in microparticle technology. Spray drying is a technology employed in microparticle preparation, consisting of the atomization of liquid in a stream of gas. In this study, the pharmaceutical properties of spray-dried ALG/HPMC microparticles with posaconazole were compared with the properties of physical mixtures of powders with equal qualitative and quantitative compositions. Posaconazole (POS) as a relatively novel antifungal was utilized as a model poorly water-soluble drug, and hard gelatin capsules were applied as a reservoir for designed formulations. A release study in 0.1 M HCl showed significantly prolonged POS release from microparticles compared to a mixture of powders. Such a relationship was not followed in simulated vaginal fluid (SVF). Microparticles were also characterized by stronger mucoadhesive properties, an increased swelling ratio, and prolonged residence time compared to physical mixtures of powders. The obtained results indicated that the pharmaceutical properties of hard gelatin capsules filled with microparticles were significantly different from hard gelatin capsules with mixtures of powders.

Superabsorbent hydrogel from cassava gum (Manihot esculenta) to release water and macronutrients

The application and development of biopolymers as water storage and macronutrient release systems are attractive due to their biocompatibility and high bioavailability in the environment. Cassava gum is a polysaccharide obtained from Manihot esculenta tubers, consisting of 80–86 % starch, with an excellent ability to form a hydrogel. The objective of this research was the synthesis of hydrogels from the copolymerization of cassava gum and polyacrylamide. The material was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry, a scanning electron microscope, and porosity to understand the formation of the new hydrogel better. The hydrogel was studied for its swelling capacity at different pH levels, its controlled release of macronutrients, and its toxicity test against Artemia saline. The swelling study shows that the hydrogels have better water absorption in more neutral media with expansion capacity (∼ 270 folds). Phosphate release began 30 min after contact with the medium and remained constant after 24 h in solution, with the hydrogels not demonstrating toxicity. Hydrogels formed satisfactorily with and without phosphate incorporated into the polymeric matrix, thus resulting in a superabsorbent and promising material for the controlled release of macronutrients.

Electrospun matrices for sustained drug release made by a PCL-chitosan blend shell and a PVA core

Core-shell electrospinning is a versatile technique for tissue engineering applications due to the possibility of uploading drugs in the core layer. The drug is protected by the shell layer that also allows its release by diffusion. The aim of the present work is the development of a drug release system for the release of doxorubicin, a chemotherapeutic agent commonly used for osteosarcoma treatment. In core–shell fibres, polycaprolactone (PCL) is often proposed for the shell layer as it is bioresorbable and biocompatible, but it is hydrophobic and lacks adhesive sites for cellular attachment. In this work, a PCL-chitosan blend was used for the shell layer to increase PCL hydrophilicity and to provide cell-recognition sites to support cell adhesion. Polyvinyl alcohol (PVA) has been used for the core layer and doxorubicin was introduced with a concentration of 100 µg/mL. Core-shell fibres of dimension of 300–500 nm were successfully obtained and doxorubicin was released in a sustained way up to 28 days.

Dual pH/redox-responsive size-switchable polymeric nano-carrier system for tumor microenvironment DTX release

Innovation chemotherapeutic nano drug delivery systems (NDDSs) with various pharmacological achievement have become one of the hopeful therapeutic strategies in cancer therapy. This study focused on low pH, and high levels of glutathione (GSH) as two prominent characteristics of the tumor microenvironment (TME) to design a novel TME-targeted pH/redox dual-responsive P (AMA-co-DMAEMA)-b-PCL-SS-PCL-b-P (AMA-co-DMAEMA) nanoparticles (NPs) for deep tumor penetration and targeted anti-tumor therapy. The positively charged NPs exhibit strong electrostatic interactions with negatively charged cell membranes, significantly enhancing cellular uptake. Moreover, these NPs possess the unique size-shrinkable property, transitioning from 98.24 ± 27.78 to 45.56 ± 20.62 nm within the TME. This remarkable size change fosters an impressive uptake of approximately 100% by MDA-MB-231 cells within just 30 min, thereby greatly improving drug delivery efficiency. This size switchability enables passive targeting through the enhanced permeability and retention (EPR) effect, facilitating deep penetration into tumors. The NPs also demonstrate improved pH/redox-triggered drug release (∼70% at 24 h) within the TME and exhibit no toxicity in cell viability test. The cell cycle results of treated cells with docetaxel (DTX)-loaded NPs revealed G2/M (84.6 ± 1.16%) arrest. The DTX-loaded NPs showed more apoptosis (62.6 ± 3.7%) than the free DTX (51.8 ± 3.2%) in treated cells. The western blot and RT-PCR assays revealed that apoptotic genes and proteins expression of treated cells were significantly upregulated with the DTX-loaded NPs vs. the free DTX (P value<.001). In conclusion, these findings suggest that this novel-engineered NPs holds promise as a TME-targeted NDDS.

Development of Graphene Oxide-Based Anticancer Drug Combination Functionalized with Folic Acid as Nanocarrier for Targeted Delivery of Methotrexate.

Graphene has become a prominent material in cancer research in recent years. Graphene and its derivatives also attract attention as carriers in drug delivery systems. In this study, we designed a graphene oxide (GO)-based methotrexate (MTX)-loaded and folic acid (FA)-linked drug delivery system. MTX and FA were bound to GO synthesized from graphite. MTX/FA/GO drug delivery system and system components were characterized using Fourier transform infrared spectroscopy (FTIR), differential calorimetric analysis (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM), zeta potential analysis, and dimension measurement (DLS) studies. SEM and TEM images confirmed the nanosheet structure of GO synthesized from graphite, and it was shown that MTX/FA binding to GO transformed the two-dimensional GO into a three-dimensional structure. FTIR and DSC graphs confirmed that oxygen atoms were bound to GO with the formation of carboxylic, hydroxyl, epoxide, and carbonyl groups as a result of the oxidation of graphite, and GO was successfully synthesized. Additionally, these analyses showed that MTX and FA bind physicochemically to the structure of GO. The in vitro Franz diffusion test was performed as a release kinetic test. The release kinetics mathematical model and correlation coefficient (R2) of MTX-loaded GO/FA nanomaterials were found to be the Higuchi model and 0.9785, respectively. Stiffness analyses showed that adding FA to this release system facilitated the entry of the drug into the cell by directing the system to target cells. As a result of the stiffness analyses, the stiffness values of the control cell group, free MTX, and MTX/FA/GO applied cells were measured as 2.34 kPa, 1.87 kPa, and 1.56 kPa, respectively. According to these results, it was seen that MTX/FA/GO weakened the cancer cells. Combined use of the MTX/FA/GO drug delivery system had a higher cytotoxic effect than free MTX on the MDA-MB-231 breast cancer cell line. The results showed that the synthesized MTX/FA/GO material has promising potential in cancer cell-specific targeted therapy for MTX as a drug delivery system.

Aptamer molecular gate functionalized mesoporous SiO2@MB controlled-release system for pollutant detection using Ti(Ⅲ) self-doped TiO2 NTs as active photoanode coupled with electrostatic modulation

Atrazine (ATZ) is a widely used herbicide that can cause serious harm to organisms and ecosystems. An immobilization-free photoelectrochemical (PEC) aptasensor has been herein developed for ATZ based on aptamer molecular gate functionalized mesoporous SiO2@MB controlled release system. Compared with traditional immobilization-based sensors, immobilization-free sensors (IFSs) avoid the modification of the recognition element on the electrode surface. Mesoporous SiO2 with large surface area and good biocompatibility can be used as nanocontainers to stably encapsulate the signal shuttle molecule methylene blue (MB). The bifunctional aptamer (APT) is used not only as the recognition element for ATZ but also as the signal switch to block or release MB. In the presence of ATZ, the specific recognition between ATZ and APT will cause the detachment of APT from the surface of SiO2, thus the molecular gate will open and release MB. Due to pH modulation, the positively charged MB can reach the surface of the negatively charged Ti(III) self-doped TiO2 NTs (Ti(III)–TiO2 NTs) electrode to act as an electron donor, which increases the photocurrent. The immobilization-free aptasensor has shown ultrasensitive detection of ATZ with a wide linear range from 1.0 pM to 100.0 nM and a low detection limit of 0.1 pM. In addition, the sensor has excellent selectivity, stability and anti-interference ability, and has been used in real water sample analysis successfully. This strategy has provided a new idea for the design of advanced immobilization-free PEC sensors for environmental pollutant detection.

Hydrogels in Biomedicine: Granular Controlled Release Systems Based on 2-Hydroxyethyl Methacrylate Copolymers. A Review

The article analyzes and summarizes the latest achievements in the field of polymer systems for controlled release devices based on hydrogel materials. Possible directions of drug delivery are presented, including the use of granular hydrogels, which work on the principle of drug sorption − release in the body. The research on the synthesis regularities, structure, properties, and prospects for the use of granular hydrogels based on 2-hydroxyethyl methacrylate (HEMA) and its copolymers, in particular with polyvinylpyrrolidone (PVP), as systems for the controlled release of substances, in particular, drugs, is analyzed.