Applications of mesoporous silica in biosensing and controlled release of insulin

Recent Advances in the Drugs and Glucose-Responsive Drug Delivery Systems for the Treatment of Diabetes: A Systematic Review

Diabetes is a common chronic metabolic disease. Different types of drugs play important roles in controlling diabetes and its complications, but there are some limitations. The glucose-responsive drug delivery system is a novel technology with potential in diabetes treatment. It could automatically release drugs in response to changes in glucose levels in the body to maintain blood glucose within a normal range. The emergence of a glucose-sensitive drug delivery system provides a more intelligent and precise way to treat diabetes. The review is carried out according to the Preferred Reporting Items for Systematic Reviews (PRISMA 2020) guidelines This review focuses on the recent advances in the drugs and different systems of glucose-sensitive drug delivery, including glucose oxidase, phenylboronic acid, Concanavalin A, and other glucose-reactive systems. Furthermore, the glucose-responsive drug delivery system combined with the application applied in hydrogels, microneedles, and nanoparticles is also explored and summarized. The new platforms to sustain the release of anti-diabetic drugs could be desirable for patients. It could lead to increased adherence and glycemic outcomes for the detection and treatment of diabetes. Furthermore, given the limitations of glucose-responsive drug delivery systems, solutions and perspectives are proposed to help the understanding and application of these systems. This review will be helpful for drug discovery and treatment of diabetes from a new perspective.

β-Cyclodextrin/dialdehyde glucan-coated keratin nanoparticles for oral delivery of insulin

Successful oral insulin administration can considerably enhance the quality of life (QOL) of diabetes patients who must frequently take insulin injections. However, Oral insulin administration is seriously hampered by gastrointestinal enzymes, wide pH range, mucus and mucosal layers, which limit insulin oral bioavailability to ≤2 %. Herein, we developed a simple, inexpensive and safe dual β-cyclodextrin/dialdehyde glucan-coated keratin nanoparticle (β-CD-K-IN-DG). The resulted β-CD-K-IN-DG not only gave the ultra-high insulin loading (encapsulation efficiency (98.52 %)), but also protected insulin from acid and enzymatic degradation. This β-CD-K-IN-DG had a notable hypoglycemic effect, there was almost 80 % insulin release after 4 h of incubation under hyperglycemic conditions. Ex vivo results confirmed that β-CD-K-IN-DG possessed high mucus-penetration ability. Transepithelial transport and uptake mechanism studies revealed that bypass transport pathway and endocytosis promoted β-CD-K-IN-DG entered intestinal epithelial cells, thus increased the bioavailability of insulin (12.27 %). The improved stability of insulin during in vivo transport implied that β-CD-K-IN-DG might be a potential tool for the effective oral insulin administration.

Polymeric nanoparticles (PNPs) for oral delivery of insulin

Successful oral insulin administration can considerably enhance the quality of life (QOL) of diabetes patients who must frequently take insulin injections. Oral insulin administration, on the other hand, is seriously hampered by gastrointestinal enzymes, wide pH range, mucus and mucosal layers, which limit insulin oral bioavailability to ≤ 2%. Therefore, a large number of technological solutions have been proposed to increase the oral bioavailability of insulin, in which polymeric nanoparticles (PNPs) are highly promising for oral insulin delivery. The recently published research articles chosen for this review are based on applications of PNPs with strong future potential in oral insulin delivery, and do not cover all related work. In this review, we will summarize the controlled release mechanisms of oral insulin delivery, latest oral insulin delivery applications of PNPs nanocarrier, challenges and prospect. This review will serve as a guide to the future investigators who wish to engineer and study PNPs as oral insulin delivery systems.

Mesoporous silica nanoparticles: An emerging approach in overcoming the challenges with oral delivery of proteins and peptides

Proteins and peptides (PPs), as therapeutics are widely explored in the past few decades, by virtue of their inherent advantages like high specificity and biocompatibility with minimal side effects. However, owing to their macromolecular size, poor membrane permeability, and high enzymatic susceptibility, the effective delivery of PPs is often challenging. Moreover, their subjection to varying environmental conditions, when administered orally, results in PPs denaturation and structural conformation, thereby lowering their bioavailability. Hence, for effective delivery with enhanced bioavailability, protection of PPs using nanoparticle-based delivery system has gained a growing interest. Mesoporous silica nanoparticles (MSNs), with their tailored morphology and pore size, high surface area, easy surface modification, versatile loading capacity, excellent thermal stability, and good biocompatibility, are eligible candidates for the effective delivery of macromolecules to the target site. This review highlights the different barriers hindering the oral absorption of PPs and the various strategies available to overcome them. In addition, the potential benefits of MSNs, along with their diversifying role in controlling the loading of PPs and their release under the influence of specific stimuli, are also discussed in length. Further, the tuning of MSNs for enhanced gene transfection efficacy is also highlighted. Since extensive research is ongoing in this area, this review is concluded with an emphasis on the potential risks of MSNs that need to be addressed prior to their clinical translation.

The development of a novel copper-loaded mesoporous silica nanoparticle as a peroxidase mimetic for colorimetric biosensing and its application in H2O2 and GSH assay

In recent years, the development of nanomaterials-based peroxidase mimics as enzyme sensors has been attracting considerable interest due to their outstanding features, including potent stability, and cost-effectiveness toward natural enzymes. In this work, mesoporous silica nanoparticles functionalized by copper (Cu-MSN) were prepared as a new artificial enzyme for the first time through the sol-gel procedure. A comprehensive investigation of the catalytic activity of Cu-MSN was done through the oxidation of chromogenic peroxidase substrates, 3,3',5,5'-tetramethylbenzidine (TMB), and (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), in the presence of H₂O₂. The results indicate that the peroxidase-like activity of the as-prepared sample is significantly higher than other nanoparticles. Additionally, for the study, a facile and rapid sensing method based on the enzyme-like activity of Cu-MSN to detect H₂O₂ and glutathione (GSH) was developed to examine the potency of the proposed biosensor. Preliminary analysis revealed that the limit of detection (LOD) of H₂O₂ and GSH is 0.2 and 0.0126 μM, in the range of 0.9-100 and 0.042-1 μM, respectively. These findings support the claims for the efficiency of the sensor in detection fields. Also, human serum was utilized as the real sample to obtain additional evidence.

Study on the Effect of Different Endoscopic Auxiliary Treatment of Gastric Mucosal Microtumor

Objective

To explore the effect of endoscopy in the treatment of gastric mucosal microtumors.

Methods

A total of 229 patients with gastric mucosal microtumors were treated in our hospital from January 2016 to December 2021. All patients were divided into three groups group A, group B, and group C. Group A was treated with a transparent cap combined with circle-assisted endoscopic resection, group B with ligator combined with circle-assisted endoscopic resection, and group C with endoscopic mucosal tumor resection. The effects of the three groups were observed.

Results

There were 47 patients in group A, 17 males, and 30 females, aged 36-69 years, with an average age of 55.6 ± 9.2 years. There were 54 patients in group B, 18 males, and 36 females, aged 38-72 years, with an average age of 57.6 ± 7.7 years. There were 128 patients in group C, 29 males, and 99 females, aged 33-78 years, with an average age of 55.6 ± 8.4 years. There is no significant difference in age and sex between group A, group B, and group C (P > 0.05). The incidence of postoperative complications in group B (66.7%) was significantly higher than that in group A (57.4%) and group C (53.9%) (all P < 0.05). The incidence of postoperative complications in group A (57.4%) was higher than that in group C (53.9%), and the difference was statistically significant (P < 0.05).

Conclusion

Endoscopic mucosal resection and ligation combined with circle-assisted endoscopic resection are effective and safe in the treatment of gastric mucosal microtumors, but it needs to be combined with targeted nursing measures. The transparent cap combined with ring-assisted endoscopic resection has a significant effect on the treatment of gastric mucosal micromasses, reducing operative complications.

Microelectromechanical Systems Based on Magnetic Polymer Films

Microelectromechanical systems (MEMS) have been increasingly used worldwide in a wide range of applications, including high tech, energy, medicine or environmental applications. Magnetic polymer composite films have been used extensively in the development of the micropumps and valves, which are critical components of the microelectromechanical systems. Based on the literature survey, several polymers and magnetic micro and nanopowders can be identified and, depending on their nature, ratio, processing route and the design of the device, their performances can be tuned from simple valves and pumps to biomimetic devices, such as, for instance, hearth ventricles. In many such devices, polymer magnetic films are used, the disposal of the magnetic component being either embedded into the polymer or coated on the polymer. One or more actuation zones can be used and the flow rate can be mono-directional or bi-directional depending on the design. In this paper, we review the main advances in the development of these magnetic polymer films and derived MEMS: microvalve, micropump, micromixer, microsensor, drug delivery micro-systems, magnetic labeling and separation microsystems, etc. It is important to mention that these MEMS are continuously improving from the point of view of performances, energy consumption and actuation mechanism and a clear tendency in developing personalized treatment. Due to the improved energy efficiency of special materials, wearable devices are developed and be suitable for medical applications.

Magnetite-Silica Core/Shell Nanostructures: From Surface Functionalization towards Biomedical Applications—A Review

The interconnection of nanotechnology and medicine could lead to improved materials, offering a better quality of life and new opportunities for biomedical applications, moving from research to clinical applications. Magnetite nanoparticles are interesting magnetic nanomaterials because of the property-depending methods chosen for their synthesis. Magnetite nanoparticles can be coated with various materials, resulting in “core/shell” magnetic structures with tunable properties. To synthesize promising materials with promising implications for biomedical applications, the researchers functionalized magnetite nanoparticles with silica and, thanks to the presence of silanol groups, the functionality, biocompatibility, and hydrophilicity were improved. This review highlights the most important synthesis methods for silica-coated with magnetite nanoparticles. From the presented methods, the most used was the Stöber method; there are also other syntheses presented in the review, such as co-precipitation, sol-gel, thermal decomposition, and the hydrothermal method. The second part of the review presents the main applications of magnetite-silica core/shell nanostructures. Magnetite-silica core/shell nanostructures have promising biomedical applications in magnetic resonance imaging (MRI) as a contrast agent, hyperthermia, drug delivery systems, and selective cancer therapy but also in developing magnetic micro devices.

Glucose-Responsive Polyelectrolyte Complexes Based on Dendritic Mesoporous Silica for Oral Insulin Delivery

The postprandial glycemic regulation is essential for diabetic patients to reduce the risk of long-term microvascular and macrovascular complications. Herein, we designed a glucose-responsive oral insulin delivery system based on polyelectrolyte complexes (PECs) for controlling the increasing postprandial glucose concentrations. Briefly, alginate-g-3-aminophenylboronic acid (ALG-g-APBA) and chitosan-g-3-fluoro-4-carboxyphenylboronic acid (CS-g-FPBA) were wrapped on mesoporous silica (MSN) to form the negative charged ALG-g-APBA@MSN and the positive charged CS-g-FPBA@MSN nanoparticles, with an optimum insulin loading capacity of 124 mg/g and 295 mg/g, respectively. ALG-g-APBA@MSN was further cross-linked with CS-g-FPBA@MSN to form PECs through electrostatic interaction and borate esters. The dense polyelectrolyte network wrapped on MSN was capable of preventing insulin from diffusion and regulating its release. The in vitro insulin release of PECs demonstrated an obvious glucose response profile in different glucose concentrations (0 mg/mL, 2 mg/mL, 5 mg/mL) and presented a switch "on" and "off" release regulation at hyperglycemic or normal state. The CCK-8 assay showed that none of the MSN, ALG-g-APBA@MSN, CS-g-FPBA@MSN, and PECs possessed cytotoxicity to Caco-2 cells. For in vivo tests, the oral PECs exhibited a significant hypoglycemic effect and maintained in the euglycemic levels up to approximately 12 h on diabetic rats. Overall, the PECs directly triggered by postprandial glucose in the intestine have a good potential to be applied in intelligent insulin delivery by the oral route.

Controlled release evaluation of paracetamol loaded amine functionalized mesoporous silica KCC1 compared to microcrystalline cellulose based tablets

In the pharmaceutical manufacturing, drug release behavior development is remained as one of the main challenges to improve the drug effectiveness. Recently, more focus has been done on using mesoporous silica materials as drug carriers for prolonged and superior control of drug release in human body. In this study, release behavior of paracetamol is developed using drug-loaded KCC-1-NH2 mesoporous silica, based on direct compaction method for preparation of tablets. The purpose of this study is to investigate the utilizing of pure KCC-1 mesoporous silica (KCC-1) and amino functionalized KCC-1 (KCC-1-NH2) as drug carriers in oral solid dosage formulations compared to common excipient, microcrystalline cellulose (MCC), to improve the control of drug release rate by manipulating surface chemistry of the carrier. Different formulations of KCC-1 and KCC-NH2 are designed to investigate the effect of functionalized mesoporous silica as carrier on drug controlled-release rate. The results displayed the remarkable effect of KCC-1-NH2 on drug controlled-release in comparison with the formulation containing pure KCC-1 and formulation including MCC as reference materials. The pure KCC-1 and KCC-1-NH2 are characterized using different evaluation methods such as FTIR, SEM, TEM and N2 adsorption analysis.

Mesoporous Silica Platforms with Potential Applications in Release and Adsorption of Active Agents

In recent years, researchers focused their attention on mesoporous silica nanoparticles (MSNs) owing to the considerable advancements of the characterization methods, especially electron microscopy methods, which allowed for a clear visualization of the pore structure and the materials encapsulated within the pores, along with the X-ray diffraction (small angles) methods and specific surface area determination by Brunauer–Emmett–Teller (BET) technique. Mesoporous silica gained important consideration in biomedical applications thanks to its tunable pore size, high surface area, surface functionalization possibility, chemical stability, and pore nature. Specifically, the nature of the pores allows for the encapsulation and release of anti-cancer drugs into tumor tissues, which makes MSN ideal candidates as drug delivery carriers in cancer treatment. Moreover, the inner and outer surfaces of the MSN provide a platform for further functionalization approaches that could enhance the adsorption of the drug within the silica network and the selective targeting and controlled release to the desired site. Additionally, stimuli-responsive mesoporous silica systems are being used as mediators in cancer therapy, and through the release of the therapeutic agents hosted inside the pores under the action of specific triggering factors, it can selectively deliver them into tumor tissues. Another important application of the mesoporous silica nanomaterials is related to its ability to extract different hazardous species from aqueous media, some of these agents being antibiotics, pesticides, or anti-tumor agents. The purpose of this paper is to analyze the methods of MSN synthesis and related characteristics, the available surface functionalization strategies, and the most important applications of MSN in adsorption as well as release studies. Owing to the increasing antibiotic resistance, the need for developing materials for antibiotic removal from wastewaters is important and mesoporous materials already proved remarkable performances in environmental applications, including removal or even degradation of hazardous agents such as antibiotics and pesticides.

Enzyme production ofd-gluconic acid and glucose oxidase: successful tales of cascade reactions

This review mainly focuses on the use of glucose oxidase in the production ofd-gluconic acid, which is a reactant of undoubtable interest in different industrial areas. As example of diverse enzymatic cascade reactions.

Enteric pH responsive cargo release from PDA and PEG coated mesoporous silica nanoparticles: a comparative study in Drosophila melanogaster

Physiological stimulus-specific cargo release from nanoparticle carriers is a holy grail of drug delivery research. While the majority of such work is carried out in vitro with cell lines, widespread use of common mammalian model systems – mice and rats – is difficult due to the associated cost and regulatory restrictions. Here we use the inexpensive, easily reared, excellent genetic model system Drosophila melanogaster to test pH responsive cargo release from widely used mesoporous silica nanoparticles (MSNs) coated with pH sensitive polydopamine (PDA) and polyethylene glycol (PEG) polymers. We synthesized 650 ± 75 nm diameter PDA or PEG coated mesoporous silica nanoparticles loaded with a fluorescent dye and fed to individual adult flies. Subsequently, the passage of the particles were monitored through the fly gut. As in mammals, the fly intestine has multiple pH specific zones that are easily accessible for imaging and also genetic, biochemical or physiological manipulations. We observed that both the species of MSNs ruptured around the acidic (pH < 4.0) middle midgut of the flies. PEG coated particles showed sharper specificity of release in the acidic middle midgut of flies than the PDA coated ones and had less tendency to clump together. Our results clearly show that the Drosophila gut can be used as a model to test pH responsive biocompatible materials in vivo. Our work paves the way for greater use of Drosophila as an in vivo complete systemic model in drug delivery and smart materials research. It also suggests that such specific delivery of chemical/biological cargo can be exploited to study basic biology of the gut cells and their communication with other organs.

Targeted delivery in Drosophila middle mid-gut at pH < 4.0.

USE OF SORPTION PROCESSES IN THE TECHNOLOGY OF DRUG DELIVERY SYSTEMS

The aimof this research is the review of scientific and technical literature regarding possibility of using sorption processes in the technology of drug delivery systems.

Materials and methods. The materials are the following electronic resources: eLIBRARY, CyberLeninka, PubMed. The methods of review are analysis and synthesis. The study covers the scientific literature from 1996 up to the present time.

Results.Sorbents are used as carriers for various medicinal peroral substances, they are also dispensers of various compounds in the form of polymeric eye films and stents in the human body. The delivery of medicinal substances occurs with the help of sorption processes of mass transfer. Currently, the following medical substances are used as carriers for medicinal substances: activated carbon, mineral sorbents (medical clays, synthetic sorbents), polymers and their biosimilars. 6 groups of pharmaceutical substances are registered for the production of enterosorbents in Russia and they can be used as sorbent carriers in the sorption drug system. They are: activated carbon, colloidal silicon dioxide, polyvinylpyrrolidone, dioctahedral smectite, polymethylsiloxane polyhydrate. As a result of the study, the model of the sorption drug system has been developed. It consists of sorbent carrier, active pharmaceutical ingredient and excipients that provide the desorption. Desorption of the active pharmaceutical ingredient may contribute to its modified release. The technology for obtaining sorption medicinal systems requires further study and development of modeling methods, searching for experimental pharmacological models and technological methods, which make it possible to obtain sorption dosage form with modified release.

Conclusion.The review of the sorption processes used in the technology of drug delivery systems has been carried out. The model of the sorption drug system has been developed.