Methylcellulose and polyacrylate binary hydrogels used as rectal suppository to prevent type I diabetes

[Evolution of insulin therapy: past, present, future]

2021 marks the 100th anniversary of the discovery of insulin, an event that forever changed the lives of people with diabetes mellitus. At present patients around the world experience the miracle of insulin therapy every day. A disease that used to kill children and teenagers in 2 years in 1920 has become a disease that can be controlled with a possibility to lead a long productive life. Over the past century, the great discovery of Banting, Best and Collip has forever changed the world and saved millions of lives. This review is devoted to the history of the development of insulin and its further improvement: from the moment of discovery to the present days. Various generations of insulin are considered: from animals to modern ultrashort and basal analogues. The article ends with a brief review of current trends in the development of new delivery methods and the development of new insulin molecules. Over the past century, insulin therapy has come a long way, which has significantly improved the quality of life of our patients. But research is actively continuing, including in the field of alternative methods of insulin delivery, which are more convenient for the patient, as well as in the development of «smart» molecules that will have a glucose-dependent effect.

Non-Invasive Delivery of Insulin for Breaching Hindrances against Diabetes

Insulin is recognized as a crucial weapon in managing diabetes. Subcutaneous (s.c.) injections are the traditional approach for insulin administration, which usually have many limitations. Numerous alternative (non-invasive) slants through different routes have been explored by the researchers for making needle-free delivery of insulin for attaining its augmented absorption as well as bioavailability. The current review delineating numerous pros and cons of several novel approaches of non-invasive insulin delivery by overcoming many of their hurdles. Primary information on the topic was gathered by searching scholarly articles from PubMed added with extraction of data from auxiliary manuscripts. Many approaches (discussed in the article) are meant for the delivery of a safe, effective, stable, and patient friendly administration of insulin via buccal, oral, inhalational, transdermal, intranasal, ocular, vaginal and rectal routes. Few of them have proven their clinical efficacy for maintaining the glycemic levels, whereas others are under the investigational pipe line. The developed products are comprising of many advanced micro/nano composite technologies and few of them might be entering into the market in near future, thereby garnishing the hopes of millions of diabetics who are under the network of s.c. insulin injections.

A Comprehensive Review of the Evolution of Insulin Development and Its Delivery Method

The year 2021 marks the 100th anniversary of the momentous discovery of insulin. Through years of research and discovery, insulin has evolved from poorly defined crude extracts of animal pancreas to recombinant human insulin and analogues that can be prescribed and administered with high accuracy and efficacy. However, there are still many challenges ahead in clinical settings, particularly with respect to maintaining optimal glycemic control whilst minimizing the treatment-related side effects of hypoglycemia and weight gain. In this review, the chronology of the development of rapid-acting, short-acting, intermediate-acting, and long-acting insulin analogues, as well as mixtures and concentrated formulations that offer the potential to meet this challenge, are summarized. In addition, we also summarize the latest advancements in insulin delivery methods, along with advancement to clinical trials. This review provides insights on the development of insulin treatment for diabetes mellitus that may be useful for clinicians in meeting the needs of their individual patients. However, it is important to note that as of now, none of the new technologies mentioned have superseded the existing method of subcutaneous administration of insulin.

3D Reconstruction and Intelligent Digital Conservation of Ancient Buildings Based on Laser Point Cloud Data

With the wide application of computer technology, how to carry out digital modeling and virtual simulation for the protection of ancient buildings has become a new research field. The combination of LiDAR (LiDAR) point cloud data can significantly improve the performance of 3D spatial information extraction of buildings. To improve the level of ancient building conservation, this article uses LiDAR point cloud data to collect ancient building data, extracts 3D spatial location information from multisource remote sensing optical stereo images, restores 3D spatial structure information of buildings from LiDAR point cloud data, conducts optimized topology research work, jointly extracts 3D spatial information of buildings with structural constraints, and compares the collected data with the original data. The research results show that the traditional data collection method has a large error of about 10%, while the data collected by LiDAR (LiDAR) point cloud data in this article is close to the original data. The error is around 3%, which can well complete the 3D reconstruction and protection of ancient buildings.

Recent progress in polymeric non-invasive insulin delivery

The design of carriers for insulin delivery has recently attracted major research attentions in the biomedical field. In general, the release of drug from polymers is driven via a variety of polymers. Several mechanisms such as matrix release, leaching of drug, swelling, and diffusion are usually adopted for the release of drug through polymers. Insulin is one of the most predominant therapeutic drugs for the treatment of both diabetes mellitus; type-I (insulin-dependent) and type II (insulin-independent). Currently, insulin is administered subcutaneously, which makes the patient feel discomfort, pain, hyperinsulinemia, allergic responses, lipodystrophy surrounding the injection area, and occurrence of miscarried glycemic control. Therefore, significant research interest has been focused on designing and developing new insulin delivery technologies to control blood glucose levels and time, which can enhance the patient compliance simultaneously through alternative routes as non-invasive insulin delivery. The aim of this review is to emphasize various non-invasive insulin delivery mechanisms including oral, transdermal, rectal, vaginal, ocular, and nasal. In addition, this review highlights different smart stimuli-responsive insulin delivery systems including glucose, pH, enzymes, near-infrared, ultrasound, magnetic and electric fields, and the application of various polymers as insulin carriers. Finally, the advantages, limitations, and the effect of each non-invasive route on insulin delivery are discussed in detail.

Rectal bioavailability of amoxicillin sodium in rabbits: Effects of suppository base and drug dose

In this paper, rectal absorption and tissue tolerance of amoxicillin sodium (AS) suppositories prepared in a hydrophilic base, polyethylene glycol (PEG) or lipophilic base, Suppocire® NA 15 (SNA 15), were investigated. Following in vitro characterization, including drug distribution in the suppository bases, drug-base interactions and drug release, pharmacokinetics were investigated in rabbits to determine absolute bioavailability (F) at two dose levels (100 mg and 200 mg). Both types of suppositories were found uniform in weight and content. Powder X-ray diffraction (XRD) and differential scanning calorimetry indicated that AS existed as solid dispersion or anhydrous crystalline dispersion in both suppositories at different ratios without changing melting points of the bases. This was supported by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy conjugated with energy dispersive X-ray (SEM/EDX). In dissolution medium, melting and spreading of SNA 15 and dissolution of PEG suppositories accounted for their different drug release kinetics and mean dissolution time (MDT). A rapid and complete amoxicillin absorption (F close to 100%) with a double peak pharmacokinetic profile was observed alongside minimal signs of tissue irritation in rabbits treated with SNA 15 suppositories at both dose levels. In contrast, the F of amoxicillin from PEG suppositories was 59%, increasing to 77.3% as AS dose doubled from 100 mg to 200 mg, reflected in the slower release predominately controlled by erosion of the base. An in vitro - in vivo correlation was observed (MDT vs F; p < 0.01). AS was stable in SNA 15 suppositories at least for three months at 20 ± 0.2 °C. This research highlighted the advantages of SNA 15 suppositories over the PEG suppositories in providing rapid and complete rectal absorption of AS and tissue compatibility.

Ultrasound-targeted microbubble destruction promotes myocardial angiogenesis and functional improvements in rat model of diabetic cardiomyopathy

BACKGROUND

Microvascular insufficiency plays an important role in the development of diabetic cardiomyopathy (DCM), therapeutic angiogenesis has been mainly used for the treatment of ischemic diseases. This study sought to verify the preclinical performance of SonoVue microbubbles (MB) combined ultrasound (US) treatment on myocardial angiogenesis in the rat model of DCM and investigate the optimal ultrasonic parameters.

METHODS

The male Sprague-Dawley (SD) rats were induced DCM by streptozotocin through intraperitoneal injecting and fed with high-fat diet. After the DCM model was established, the rats were divided into the normal group, DCM model group, and US + MB group, while the US + MB group was divided into four subsets according to different pulse lengths (PL) (8 cycles;18 cycle;26 cycle; 36 cycle). After all interventions, all rats underwent conventional echocardiography to examine the cardiac function. The rats were sacrificed and myocardial tissue was examined by histology and morphometry evaluations to detect the myocardial protective effect of SonoVue MBs using US techniques.

RESULTS

From morphologic observation and echocardiography, the DCM rats had a series of structural abnormalities of cardiac myocardium compared to the normal rats. The US-MB groups exerted cardioprotective effect in DCM rats, improved reparative neovascularization and increased cardiac perfusion, while the 26 cycle group showed significant therapeutic effects on the cardiac functions in DCM rats.

CONCLUSION

This strategy using SonoVue MB and US can improve the efficacy of angiogenesis, even reverse the progress of cardiac dysfunction and pathological abnormalities, especially using the 26 cycle parameters. Under further study, this combined strategy might provide a novel approach for early intervention of DCM in diabetic patients.

Puerarin-loaded ultrasound microbubble contrast agent used as sonodynamic therapy for diabetic cardiomyopathy rats

In this study, a puerarin-loaded ultrasound sulfur hexafluoride microbubble contrast agent as a sonodynamic therapy (SDT) was developed to improve targeted drug delivery and pharmacodynamic effects in diabetic cardiomyopathy (DCM) treatment. Fluorescence microscope morphology was applied to confirm the fabrication of the puerarin - microbubbles (PMBs). The average size distribution and zeta potential of PMBs were 760.0 ± 101.2 nm and -20.4 ± 6.59 mV, respectively. In vitro and in vivo experiments were carried out to study the pharmacodynamic effects and targeted drug delivery of PMBs. The cytotoxicity, assessed by the cell viability of human umbilical vein endothelial cells (HUVECs), showed that the microbubbles were nontoxic even in high concentration of 2.500 mg/mL, and the wound healing scratch assay proved that PMBs cloud obviously improve the migration ability of HUVECs. Furthermore, streptozotocin (STZ) accompanied with high-energy diets was employed to build the DCM rat model. The blood glucose, histological changes of the pancreas and heart, and cardiac function were used to confirm the obtainment of the DCM rat model. Histological and physiological changes of the PMBs treatment group indicated that PMBs had a significant therapeutic efficacy when compared to the DCM model group. Therefore, PMBs are a promising strategy for a targeted drug delivery system and a novel noninvasive treatment for DCM.

Recent Advancements in Non-Invasive Formulations for Protein Drug Delivery

Advancements in biotechnology and protein engineering expand the availability of various therapeutic proteins including vaccines, antibodies, hormones, and growth factors. In addition, protein drugs hold many therapeutic advantages over small synthetic drugs in terms of high specificity and activity. This has led to further R&D investment in protein-based drug products and an increased number of drug approvals for therapeutic proteins. However, there are many biological and biopharmaceutical obstacles inherent to protein drugs including physicochemical and enzymatic destabilization, which limit their development and clinical application. Therefore, effective formulations of therapeutic proteins are needed to overcome the various physicochemical and biological barriers. In current medical practice, protein drugs are predominantly available in injectable formulations, which have disadvantages including pain, the possibility of infection, high cost, and low patient compliance. Consequently, non-invasive drug delivery systems for therapeutic proteins have gained great attention in the research and development of biomedicines. Therefore, this review covers the various formulation approaches to optimizing the delivery properties of protein drugs with an emphasis on improving bioavailability and patient compliance. It provides a comprehensive update on recent advancements in nanotechnologies with regard to non-invasive protein drug delivery systems, which is also categorized by the route of administrations including oral, nasal, transdermal, pulmonary, ocular, and rectal delivery systems.