Preparation, characterization and in vitro release study of drug-loaded sodium carboxy-methylcellulose/chitosan composite sponge

Multi-layer encapsulation of pumpkin (Cucurbita maxima L.) seed protein hydrolysate and investigating its release and antioxidant activity in simulated gastrointestinal digestion

Because of their high protein content, easy access and low cost, pumpkin seeds are a valuable raw material for the preparation of antioxidant protein hydrolysates. Micro-coating is an effective method to protect bioactive compounds against destruction. In order to strengthen the alginate hydrogel network loaded with pumpkin seed protein hydrolysate (PSPH), CMC was added as part of its formulation in the first step, and chitosan coating was used in the second step. Then, swelling amount, release in the simulated gastrointestinal environment (SGI), antioxidant activity after SGI, Fourier transform infrared spectroscopy (FTIR), zeta potential, dynamic light scattering (DLS), polydispersity index (PDI) and scanning electron microscopy (SEM) of the samples were evaluated. The results showed that, the swelling amount of the chitosan-alginate hydrogel was lower than the chitosan-alginate-CMC sample, and with the increase in chitosan concentration, the swelling amount decreased. The release amount in the chitosan-alginate sample was higher than that in the chitosan-alginate-CMC sample, and with the increase in chitosan concentration, the release rate decreased. Also, the amount of release increased with the passage of time. The highest antioxidant activity belonged to the chitosan-alginate sample in SGI, and it increased with increasing the chitosan concentration. All findings demonstrated that the use of multi-component hybrid systems is a useful method for the protection of bioactive compounds against destruction, their antioxidant activities and their release behavior.

Chitosan sponges loaded with metformin and microalgae as dressing for wound healing: A study in diabetic bio-models

Among the conditions caused by diabetes, the diabetic foot is a significant public health problem due to its delayed healing process. That makes it essential to design, manufacture, and apply auxiliary dressings during healing. In this work, chitosan sponges were developed and evaluated as wound dressings. Metformin, fucoidan, and exopolysaccharide from Porphyridium purpureum algae were loaded into the sponges and studied as healing promoters. The composite sponges were physicochemically, morphologically, and thermally characterized, allowing us to determine the chemical mechanisms involved in the sponge formation. The mechanical analysis demonstrated that sponge composites have shape memory and good mechanical performance under compression stress, showing a compressive strength above 30 kPa. These results correlated with the materials' porosity, influencing the swelling capacity that reached a maximum of 70 %. The morphology of materials was observed by SEM, resulting in folded films with surface porosity. The results of the biocompatibility tests confirmed that the materials are not cytotoxic or hemolytic and have good antibacterial activity. In vivo wound healing evaluation showed that metformin-loaded chitosan sponges regenerated skin tissue after 21 days of treatment, highlighting the rate of healing provided when exopolysaccharide was added to promote tissue regeneration, which can be corroborated by histological analysis. These results make chitosan sponge compounds promising dressings for diabetic foot wound treatment.

Sustained drug release behavior of captopril-incorporated chitosan/carboxymethyl cellulose biomaterials for antihypertensive therapy

Captopril (CTP) is an oral drug widely used to treat high blood pressure and congestive heart failure. In this study, CTP-incorporated biomaterials for antihypertensive therapy were synthesized from chitosan, carboxymethyl cellulose, and plasticizers. The physicochemical properties of the prepared biomaterials were characterized using FE-SEM, FT-IR analysis, and physical properties. CTP release experiments were carried out in buffer solutions at various pH values and temperatures. Results indicated that above 99.0 % of CTP was released within 180 min. Optimization of the experimental conditions for CTP release was analyzed by using response surface methodology (RSM). Results of CTP release through artificial skin indicated that CTP was continuously released above 95.0 % from the prepared biomaterials for 36.0 h. The CTP release mechanisms into a buffer and through artificial skin followed pseudo-Fickian diffusion mechanism and non-Fickian diffusion mechanisms, respectively. Moreover, angiotensin-converting enzyme (ACE) inhibition (related to cardiovascular disease) via the released CTP clearly reveals that the prepared biomaterials have a high potential as a transdermal drug delivery agent in antihypertensive therapy.

Flavonoid-Loaded Biomaterials in Bone Defect Repair

Skeletons play an important role in the human body, and can form gaps of varying sizes once damaged. Bone defect healing involves a series of complex physiological processes and requires ideal bone defect implants to accelerate bone defect healing. Traditional grafts are often accompanied by issues such as insufficient donors and disease transmission, while some bone defect implants are made of natural and synthetic polymers, which have characteristics such as good porosity, mechanical properties, high drug loading efficiency, biocompatibility and biodegradability. However, their antibacterial, antioxidant, anti-inflammatory and bone repair promoting abilities are limited. Flavonoids are natural compounds with various biological activities, such as antitumor, anti-inflammatory and analgesic. Their good anti-inflammatory, antibacterial and antioxidant activities make them beneficial for the treatment of bone defects. Several researchers have designed different types of flavonoid-loaded polymer implants for bone defects. These implants have good biocompatibility, and they can effectively promote the expression of angiogenesis factors such as VEGF and CD31, promote angiogenesis, regulate signaling pathways such as Wnt, p38, AKT, Erk and increase the levels of osteogenesis-related factors such as Runx-2, OCN, OPN significantly to accelerate the process of bone defect healing. This article reviews the effectiveness and mechanism of biomaterials loaded with flavonoids in the treatment of bone defects. Flavonoid-loaded biomaterials can effectively promote bone defect repair, but we still need to improve the overall performance of flavonoid-loaded bone repair biomaterials to improve the bioavailability of flavonoids and provide more possibilities for bone defect repair.

Cr (VI) and Pb (II) Removal Using Crosslinking Magnetite-Carboxymethyl Cellulose-Chitosan Hydrogel Beads

Heavy metals, such as chromium (VI) and lead (II), are the most common pollutants found in wastewater. To solve these problems, this research was intended to synthesize magnetite hydrogel beads (CMC-CS-Fe3O4) by crosslinking carboxymethyl cellulose (CMC) and chitosan (CS) and impregnating them with iron oxide (Fe3O4) as a potential adsorbent to remove Cr (VI) and Pb (II) from water. CMC-CS-Fe3O4 was characterized by pHzpc, scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). Batch removal experiments with different variables (CMC:CS ratio, pH, initial metals concentration, and contact time) were conducted, and the results revealed that CMC-CS-Fe3O4 with a CMC:CS (3:1) ratio had the best adsorption capacity for Cr (VI) and Pb (II) at pH levels of 2 and 4, respectively. The findings of this research revealed that the maximum adsorption capacity for Cr (VI) and Pb (II) were 3.5 mg/g and 18.26 mg/g, respectively, within 28 h at 30 ℃. The adsorption isotherm and adsorption kinetics suggested that removal of Cr (VI) and Pb (II) were fitted to Langmuir and pseudo-second orders. The highest desorption percentages for Cr (VI) and Pb (II) were 70.43% and 83.85%, achieved using 0.3 M NaOH and 0.01 M N·a2EDTA, respectively. Interestingly, after the first cycle of the adsorption-desorption process, the hydrogel showed a sudden increase in adsorption capacity for Cr (VI) and Pb (II) until it reached 7.7 mg/g and 33.0 mg/g, respectively. This outcome may have certain causes, such as entrapped metal ions providing easy access to the available sites inside the hydrogel or thinning of the outer layer of the beads leading to greater exposure toward active sites. Hence, CMC-CS-Fe3O4 hydrogel beads may have potential application in Cr (VI) and Pb (II) removal from aqueous solutions for sustainable environments.

Dendrobium officinale Enzyme Changing the Structure and Behaviors of Chitosan/γ-poly(glutamic acid) Hydrogel for Potential Skin Care

Hydrogels have been widespreadly used in various fields. But weak toughness has limited their further applications. In this study, Dendrobium officinale enzyme (DOE) was explored to improve chitosan/γ-poly(glutamic acid) (CS/γ-PGA) hydrogel in the structure and properties. The results indicated that DOE with various sizes of ingredients can make multiple noncovalent crosslinks with the skeleton network of CS/γ-PGA, significantly changing the self-assembly of CS/γ-PGA/DOE hydrogel to form regular protuberance nanostructures, which exhibits stronger toughness and better behaviors for skin care. Particularly, 4% DOE enhanced the toughness of CS/γ-PGA/DOE hydrogel, increasing it by 116%. Meanwhile, water absorption, antioxygenation, antibacterial behavior and air permeability were increased by 39%, 97%, 27% and 52%.

Silk Fibroin-Based Biomaterials for Hemostatic Applications

Hemostasis plays an essential role in all surgical procedures. Uncontrolled hemorrhage is the primary cause of death during surgeries, and effective blood loss control can significantly reduce mortality. For modern surgeons to select the right agent at the right time, they must understand the mechanisms of action, the effectiveness, and the possible adverse effects of each agent. Over the past decade, various hemostatic agents have grown intensely. These agents vary from absorbable topical hemostats, including collagen, gelatins, microfibrillar, and regenerated oxidized cellulose, to biologically active topical hemostats such as thrombin, biological adhesives, and other combined agents. Commercially available products have since expanded to include topical hemostats, surgical sealants, and adhesives. Silk is a natural protein consisting of fibroin and sericin. Silk fibroin (SF), derived from silkworm Bombyx mori, is a fibrous protein that has been used mostly in fashion textiles and surgical sutures. Additionally, SF has been widely applied as a potential biomaterial in several biomedical and biotechnological fields. Furthermore, SF has been employed as a hemostatic agent in several studies. In this review, we summarize the several morphologic forms of SF and the latest technological advances on the use of SF-based hemostatic agents.

Synthesized nano particles of glimepiride via spray freezing into cryogenic liquid: characterization, antidiabetic activity, and bioavailability

The aim of this work was to formulate glimepiride (class II drug) which is characterized by low solubility and high permeability as nanostructured particles using a cryogenic technique with an aid of water-soluble polymer to improve its aqueous solubility and hence its bioavailability. 27 formula of glimepiride nano size particles were prepared by a spray freezing into cryogenic liquid (SCFL) using poly vinyl pyrrolidone K-30 (PVP K-30); that three drug polymer ratio (1:1, 1:2, and 1:3), with three different volumes of feeding solution (50, 100, 150 mL), at three flow rates (10, 20, and 30 mL/min). The prepared formulations were evaluated for production yield, particle size, zeta potential, drug content, release rate, in vivo hypoglycemic activity, and bioavailability. All prepared formulations showed high production yield and drug content ranged between 91.1 ± 3.4% and 94.3 ± 1.8% and 95.1 ± 2.8% and 97.1 ± 2.5%, respectively. The mean particles size was ranged between 280 ± 62 nm and 520 ± 30 nm. The results of in vitro release study revealed significant enhancement in the solubility of prepared formulations compared with the pure drug. It was found that optimal formula showed a significant reduction in blood glucose levels in diabetic rats, and 1.79-fold enhancements in oral bioavailability compared with market tablets. Nanoparticle prepared by SCFL method is an encouraging formula for improving the solubility and the bioavailability of glimepiride.

O-carboxymethyl chitosan based pH/hypoxia-responsive micelles relieve hypoxia and induce ROS in tumor microenvironment

The hypoxia in tumor microenvironment (TME) can upregulate the HIF-1α and PD-L1 expression and cause immunosuppression of tumor. In this study, a carboxymethyl chitosan-based pH/hypoxia-responsive and γ-Fe₂O₃/isosorbide dinitrate carrying micelle was designed, and it could catalyze endogenous H₂O₂ to generate oxygen and relieve hypoxia in TME, so as to relieve the overexpression of HIF-1α and PD-L1 in tumor; meanwhile, it could react with H₂O₂ to release ROS via Fenton reaction and induce cytotoxicity in tumor. Along with these multiple effects, this carboxymethyl chitosan-based micelles could provide a comprehensive strategy for tumor treatment.

Formulation of Microwave-Assisted Natural-Synthetic Polymer Composite Film and Its Physicochemical Characterization

This study is aimed at microwave-assisted synthesis of sodium carboxymethylcellulose and Eudragit L100 composite film and its physicochemical characterization. The film was developed with varying quantities of each polymer and treated with microwave at a fixed frequency of 2450 MHz with a power of 350 Watts for 60 and 120 s. All formulations were characterized for thickness/weight uniformity, moisture adsorption, erosion and water uptake, tensile strength, and vibrational, thermal, and surface morphological analysis in comparison with untreated film samples. Results indicated that microwave treatment for 60 s significantly improved the tensile strength, reduced the water adsorption, delayed erosion, and reduced the water uptake in comparison with the untreated and 120 s treated film formulations. The vibrational analysis revealed rigidification of hydrophilic domains at OH/NH moiety and fluidization of hydrophobic domains at asymmetric and symmetric CH moieties, which is envisaged to be due to the formation of new linkages between the two polymers. These were later confirmed by thermal analysis where a significant rise in transition temperature, as well as enthalpy of the system, was recorded. The microwave treatment for 60 s is thus advocated to be the best treatment condition for developing sodium carboxymethylcellulose and Eudragit L100 composite polymeric films.

Recent advancements in cellulose-based biomaterials for management of infected wounds

INTRODUCTION

Chronic wounds are a substantial burden on the healthcare system. Their treatment requires advanced dressings, which can provide a moist wound environment, prevent bacterial infiltration, and act as a drug carrier. Cellulose is biocompatible, biodegradable, and can be functionalized according to specific requirements, which makes it a highly versatile biomaterial. Antimicrobial cellulose dressings are proving to be highly effective against infected wounds.

AREAS COVERED

This review briefly addresses the mechanism of wound healing and its pathophysiology. It also discusses wound infections, biofilm formation, and progressive emergence of drug-resistant bacteria in chronic wounds and the treatment strategies for such types of infected wounds. It also summarizes the general properties, method of production, and types of cellulose wound dressings. It explores recent studies and advancements regarding the use of cellulose and its derivatives in wound management.

EXPERT OPINION

Cellulose and its various functionalized derivatives represent a promising choice of wound dressing material. Cellulose-based dressings loaded with antimicrobials are very useful in controlling infection in a chronic wound. Recent studies showing its efficacy against drug-resistant bacteria make it a favorable choice for chronic wound infections. Further research and large-scale clinical trials are required for better clinical evidence of its efficiency.

Key advances of carboxymethyl cellulose in tissue engineering & 3D bioprinting applications

Carboxymethyl cellulose (CMC) is a water-soluble derivative of cellulose and a major type of cellulose ether prepared by the chemical attack of alkylating reagents on the activated non-crystalline regions of cellulose. It is the first FDA approved cellulose derivative which can be targeted for desired chemical modifications. In this review, the properties along with current advances in the physical and chemical modifications of CMC are discussed. Further, CMC and modified CMC could be engineered to fabricate scaffolds for tissue engineering applications. In recent times, CMC and its derivatives have been developed as smart bioinks for 3D bioprinting applications. From these perspectives, the applications of CMC in tissue engineering and current knowledge on peculiar features of CMC in 3D and 4D bioprinting applications are elaborated in detail. Lastly, future perspectives of CMC for wider applications in tissue engineering and 3D/4D bioprinting are highlighted.

Carboxymethyl cellulose-based materials for infection control and wound healing: A review

The development of ideal wound dressing materials with excellent characteristics is currently a major demand in wound therapy. In recent years, carboxymethyl cellulose (CMC)-based wound dressing materials have been of immense attraction due to their noble properties, such as: biocompatibility, biodegradability, tissue resembling, low cost and non-toxic. It is used extensively, in a variety of applications in the biomedical and pharmaceutical fields. The hydrophilic nature of CMC, makes it possible to blend and cross-link with other materials, such as: synthetic polymers, natural polymers and inorganic materials and it enables the preparation of innovative wound dressing biomaterials. Hence, this review, focuses on the intrinsic characteristics of CMC-based wound dressing materials, including hydrogels, films, 3D printing, fibres, gauzes and their recent advancements in chronic wound healing.

Nanoparticles of Lovastatin: Design, Optimization and in vivo Evaluation

Introduction

The aim of the study was to optimize the processing factors of precipitation–ultrasonication technique to prepare nano-sized particles of Lovastatin (LA) for enhancing its solubility, dissolution rate and in vivo bioavailability.

Methods

LA nanoparticles (LANs) were prepared using precipitation–ultrasonication technique under different processing factors. LANs were characterized in terms of particle size, zeta potential and in vitro release. Stability studies at 4°C, 25°C and 40°C were conducted for optimum formulation. In addition, the in vivo bioavailability of the optimum formula was studied in comparison to a marketed product in white master rats.

Results

The optimized LAN formula (LAN15) had particle size (190±15), polydispersity index (0.626±0.11) and a zeta potential (−25±1.9 mV). The dissolution study of the nanosuspensions showed significant enhancement compared with pure drug. After 50 min, only 20.12±1.85% of LA was dissolved while 99.1±1.09% of LA was released from LAN15. Stability studies verified that nanosuspensions at 4°C and 25°C showed higher stability with no particle growth compared to the samples studied at 40°C. In vivo studies conducted in rats verified that there was 1.45-fold enhancement of C_max of LAN15 as compared to marketed tablets.

Conclusion

Nanoparticle prepared by ultrasonication-assisted precipitation method is a promising formula for enhancing the solubility and hence the bioavailability of Lovastatin.

Resveratrol Nanoparticles: A Promising Therapeutic Advancement over Native Resveratrol

The importance of fruit-derived resveratrol (RES) in the treatment of various diseases has been discussed in various research publications. Those research findings have indicated the ability of the molecule as therapeutic in the context of in vitro and in vivo conditions. Mostly, the application of RES in in vivo conditions, encapsulation processes have been carried out using various nanoparticles that are made of biocompatible biomaterials, which are easily digested or metabolized, and RES is absorbed effectively. These biomaterials are non-toxic and are safe to be used as components in the biotherapeutics. They are made from naturally available by-products of food materials like zein or corn or components of the physiological system as with lipids. The versatility of the RES nanoparticles in their different materials, working range sizes, specificity in their targeting in various human diseases, and the mechanisms associated with them are discussed in this review.

Fabrication and characterization of a novel semi-interpenetrating network hydrogel based on sodium carboxymethyl cellulose and poly(methacrylic acid) for oral insulin delivery

In this research, pH-sensitive semi-interpenetrating polymer network hydrogels based on sodium carboxymethyl cellulose and poly(methacrylic acid) were synthesized using free radical polymerization and semi-interpenetrating polymer network approach for oral administration of insulin. The chemical structure and thermal stability of the hydrogels were characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis measurements. The interior morphology was observed by scanning electron microscopy and the inner structure exhibited a porous honeycomb-like shape. The investigations on the swelling properties of hydrogels revealed their ability to response to pH value change. The in vitro release behavior of insulin was pH dependent and the release of insulin was much lower at pH 1.2 compared to pH 6.8. In vitro cytotoxicity assay indicated that the hydrogels were noncytotoxic to HeLa cells. A sustained reduction in blood glucose level was observed after oral administration of insulin-loaded hydrogel to diabetic rats at 75 IU/kg. These results indicated that the hydrogel would be a promising vehicle for oral insulin delivery systems.