Insulin-loaded hydroxypropyl methyl cellulose-co-polyacrylamide-co-methacrylic acid hydrogels used as rectal suppositories to regulate the blood glucose of diabetic rats

Development of injectable in situ hydrogels based on hyaluronic acid via Diels-Alder reaction for their antitumor activities studies

The objective of this study was to develop an injectable hydrogel based on furfuryl amine-conjugated hyaluronic acid (FA-conj-HA) and evaluate the in vivo anti-4 T1 tumor activity of doxorubicin-loaded hydrogel (DOX@FA-conj-HAgel). The cargo-free hydrogel (FA-conj-HAgel) was fabricated through a Diels-Alder reaction at 37 °C with FA-conj-HA as a gel material and four armed poly(ethylene glycol)2000-maleimide (4-arm-PEG2000-Mal) as a cross-linker. The bio-safety of FA-conj-HAgel were assessed, and the in vivo antitumor activity of DOX@FA-conj-HAgel was also investigated. Many 3D network structures were observed from scanning electron microscope (SEM) photograph, confirming the successful preparation of FA-conj-HAgel. The absence of cytotoxicity from FA-conj-HAgel was proved by the high viability of 4 T1 cells. In vivo bio-safety studies suggested that the obtained FA-conj-HAgel did not induce acute toxicity or other lesions in treated mice, confirming its high bio-safety. The reduced tumor volumes, hematoxylin-eosin staining (H&E), and TdT-mediated dUTP-biotin nick end labeling (TUNEL) analysis indicated the potent in vivo anti-4 T1 tumor effects of DOX@FA-conj-HAgel. In conclusion, the favorable bio-safety and potent antitumor activity of DOX@FA-conj-HAgel highlighted its potential application in oncological therapy.

Exploiting Apical Sodium-Dependent Bile Acid Transporter (ASBT)-Mediated Endocytosis with Multi-Functional Deoxycholic Acid Grafted Alginate Amide Nanoparticles as an Oral Insulin Delivery System

OBJECTIVE

Oral administration of insulin is a potential candidate for managing diabetes. However, it is obstructed by the gastrointestinal tract barriers resulting in negligible oral bioavailability.

METHODS

This investigation presents a novel nanocarrier platform designed to address these challenges. In this regard, the process involved amination of sodium alginate by ethylene diamine, followed by its conjugation with deoxycholic acid.

RESULTS

The resulting DCA@Alg@INS nanocarrier revealed a significantly high insulin loading content of 63.6 ± 1.03% and encapsulation efficiency of 87.6 ± 3.84%, with a particle size of 206 nm and zeta potentials of -3 mV. In vitro studies showed sustained and pH-dependent release profiles of insulin from nanoparticles. In vitro cellular studies, confocal laser scanning microscopy and flow cytometry analysis confirmed the successful attachment and internalization of DCA@Alg@INS nanoparticles in Caco-2 cells. Furthermore, the DCA@Alg@INS demonstrated a superior capacity for cellular uptake and permeability coefficient relative to the insulin solution, exhibiting sixfold and 4.94-fold enhancement, respectively. According to the uptake mechanism studies, the results indicated that DCA@Alg@INS was mostly transported through an energy-dependent active pathway since the uptake of DCA@Alg@INS by cells was significantly reduced in the presence of NaN3 by ~ 92% and at a low temperature of 4°C by ~ 94%.

CONCLUSIONS

Given the significance of administering insulin through oral route, deoxycholic acid-modified alginate nanoparticles present a viable option to surmount various obstacles presented by the gastrointestinal.

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.

Synthesis of the pH-sensitive nanoparticles based on the acylhydrazone bonds conjugated doxorubicin and studies on their in vivo anti-tumor effects

The purpose of this study was to synthesize DHPD polymers through the conjugation of doxorubicin (DOX) molecules onto poly(ethylene glycol) (PEG) chains via acylhydrazone bonds, and to fabricate pH-responsive DHPD nanoparticles (NPs) for investigation of their biosecurity and in vivo anti-tumor activity. The morphology, size distribution, stability, pH-responsiveness, biosecurity, and in vivo anti-tumor effects of the DHPD NPs were evaluated. Characterization of the DHPD polymers using 1H NMR, FTIR, and Raman spectra confirmed their successful synthesis. The DHPD NPs exhibited a round morphology with an average diameter of 144.4 ± 1.7 nm and a polydispersity index (PDI) of 0.23 ± 0.02. Biosecurity studies indicated that the DHPD NPs were non-toxic to treated mice, and in vitro cell tests demonstrated their ability to be taken up by 4T1 cells. Under the acidic microenvironment of 4T1 cells, the acylhydrazone bonds were cleaved, resulting in increased DOX delivery to tumor cells and improved in vivo anti-tumor effects. Animal experiments confirmed that the DHPD NPs reduced DOX toxicity while enhancing its anti-tumor activity. Furthermore, results from the analysis of γ-interferon (INF-γ), tumor necrosis factor-α (TNF-α), epidermal growth factor (EGF), and vascular endothelial growth factor (VEGF) indicated that the DHPD NPs improved the anti-4T1 tumor effect of DOX, suggesting their potential application in the treatment of breast cancer.

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.

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.

Novel β-cyclodextrin based copolymers: fabrication, characterization and in vitro release behavior

A novel cyclodextrin-contained copolymer poly(AAc-co-SA-AC-co-allyl-β-CD) was synthesized based on the method of redox radical polymerization. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (¹H NMR) spectra were used to study the structure of the obtained copolymer. The molecular weight of the copolymer was studied by gel permeation chromatography (GPC). The polymeric nanoparticles (NPs) were fabricated by a solvent evaporation method. The morphology and particle size distribution of the cargo-free NPs were investigated with transmission electron microscope (TEM), atomic force microscope (AFM), and laser particle analyzer, respectively. Curcumin (Cur) was selected as a model drug and encapsulated into the above NPs. The distribution of Cur in the drug-loaded NPs was analyzed by the method of differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Moreover, the release profiles of Cur from Cur-loaded NPs were studied in pH 6.8 and 7.4 buffers. The results of FTIR and ¹H NMR spectra confirmed the successful synthesis of poly(AAc-co-SA-AC-co-allyl-β-CD). GPC curve proved that the molecular weight of the copolymer was more than 60 kDa. TEM and AFM images illustrated that the cargo-free NPs were in spherical shape with a diameter about 40 nm. XRD patterns and DSC curves indicated that most of Cur distributed in the Cur-loaded NPs with amorphous state. Importantly, the medicated NPs showed sustained release characteristics toward Cur.

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.

Fabrication of poly(t-butyl betaine carboxylate)-based nanoparticles and study on their in vivo biosecurity

The purpose of this article was to fabricate the novel poly(t-butyl betaine carboxylate)-S-S-poly (1, 3-dioxan-2-one) nanoparticles (PCB-tBU-S-S-PDI NPs) and study their in vivo biosecurity. The poly(t-butyl betaine carboxylate) (PCB-tBU) segment was conjugated to the poly(1, 3-dioxan-2-one)(PDI) moity with a disulfide bond to obtain the copolymer PCB-tBU-S-S-PDI. Hydrogen nuclear magnetic resonance (¹H NMR) and Fourier transform infrared spectroscopy (FTIR) spectra were applied to study the structure of PCB-tBU-S-S-PDI. The cargo-free NPs were administrated to Sprague-Dawley (SD) rats by intraperitoneal injection every 3 days for 30 days. Then, the blood routine examination, blood biochemistry, and histologic slides of rat's organs were carried out to monitor the in vivo biosecurity of cargo-free PCB-tBU-S-S-PDI NPs. ¹H NMR and FTIR spectra confirmed the successfully synthesis of PCB-tBU-S-S-PDI. The cargo-free NPs showed spherical morphology with an average of 139.8 ± 0.26 nm. The results of blood biochemistry and blood routine examination suggested that the cargo-free PCB-tBU-S-S-PDI NPs did not show any influence on the liver and renal functions of treated rats. Significantly, the physiological slides of treated rat's organs did not show any physiological and pathological changes. These phenomena suggested that the PCB-tBU-S-S-PDI NPs had good biosecurity, and it could be used as a vehicle for antineoplastic drug delivery.

Application of Nanocellulose Derivatives as Drug Carriers; A Novel Approach in Drug Delivery

BACKGROUND

The production of nanocellulose for drug delivery systems has achieved increased attention in the past decade. High capacity for swelling and absorption of the liquid phase, high flexibility in creating different derivatives, economical cost, and ease of access to the primary source, all of these properties have encouraged researchers to use nanocellulose and its derivatives as a high-performance drug carrier.

OBJECTIVE

The recent progress summary of cellulose-based nanocarriers designing and practical approaches in drug delivery.

METHODS

We conducted a literature review on the development of the nanocellulose and its derivatives as a high-performance drug carrier.

RESULTS

In this review, we have attempted to present the latest advances in cellulose modifications for the design of pharmaceutical nanocarriers. At first, cellulose properties and structural classification of nanocellulose were introduced. Then, focusing on medical applications, some efforts and laboratory trials in cellulose-based nano designing were also discussed. The findings demonstrate the benefits of nanocellulose in drug delivery and its potential for modifying by adding functional groups to enhance drug delivery efficiency. Due to the physical and chemical properties of cellulose and its high flexibility to interact with other compounds, a broad perspective can be imagined in the diverse research and novel forms of nanocarriers.

CONCLUSION

The cellulose nanocarriers can be considered as an attractive platform for researchers to design new structures of pharmaceutical carriers and increase the efficiency of these nanocarriers in drug delivery for the treatment of diseases such as cancer.

Novel amino-β-Cyclodextrins containing polymers: Fabrication, characterization, and biological evaluation

In this study, poly (mPEGMA-co-MAA) (PA) based on monomers of mPEGMA and MAA were synthesized, and different amino-β-Cyclodextrins with various alkyl chains were conjugated to PA through carbodiimide-mediated coupling reactions. The obtained poly (mPEGMA-co-MAA-g-amino-β-CD) (PA-g-amino-β-CD) was characterized by FTIR, NMR and TGA. The fluorescence technique was used to investigate the micellization of PA-g-amino-β-CDs. The results indicated that these polymers could self-assemble into nano-micelles in water, and PA-g-HDA-β-CD possessed the lowest CMC value due to its long alkyl chains. In addition, the PA-g-HDA-β-CD micelles were in spherical shapes with the diameter of 78.5 ± 0.6 nm.The release of the model drug from PA-g-HDA-β-CD micelles was increased as the pH reduced from 7.4-5.5 at 37 °C. Cytotoxicity and cellular uptake experiments were performed in HepG2, which showed that the cargo-free PA-g-HDA-β-CD micelles did not have obvious cytotoxicity and were mainly distributed in the cytoplasm of HepG2 cells by endocytosis. Moreover, the study about in vivo distribution of the experimental rats indicated that the accumulation of PA-g-HDA-β-CD micelles mainly happened in the liver. Therefore, the novel amino-β-CD containing polymers exhibit good potential applications in drug delivery system.

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.

Physiological and Pharmaceutical Considerations for Rectal Drug Formulations

Although the oral route is the most convenient route for drug administration, there are a number of circumstances where this is not possible from either a clinical or pharmaceutical perspective. In these cases, the rectal route may represent a practical alternative and can be used to administer drugs for both local and systemic actions. The environment in the rectum is considered relatively constant and stable and has low enzymatic activity in comparison to other sections of the gastrointestinal tract. In addition, drugs can partially bypass the liver following systemic absorption, which reduces the hepatic first-pass effect. Therefore, rectal drug delivery can provide significant local and systemic levels for various drugs, despite the relatively small surface area of the rectal mucosa. Further development and optimization of rectal drug formulations have led to improvements in drug bioavailability, formulation retention, and drug release kinetics. However, despite the pharmaceutical advances in rectal drug delivery, very few of them have translated to the clinical phase. This review will address the physiological and pharmaceutical considerations influencing rectal drug delivery as well as the conventional and novel drug delivery approaches. The translational challenges and development aspects of novel formulations will also be discussed.

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.