Controlled Delivery Systems Research Articles

Development of chitosan-graphene oxide blend nanoparticles for controlled flurbiprofen delivery

The use of natural polymeric nanoparticles (Nps) as drug carriers is a highly promising area of research in the field of drug delivery systems because of their high efficiency. In this study, flurbiprofen (FB) loaded chitosan-graphene oxide (CS-GO) blend Nps were synthesized as a controlled delivery system using the emulsion method. The crystalline, molecular, and morphological structures of the prepared CS-GO Nps were characterized using a variety of analytical methods, including Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-Ray diffractometry (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). It was found that the introduction of GO into the CS nanoparticle formulation increased its thermal stability. The range of the average particle size was between 362 ± 5.06 and 718 ± 2.21 nm, with negative zeta potential values between −7.67 ± 4.16 and − 27.93 ± 2.26 mV. The effects of the CS/GO ratio, the FB/polymer ratio, the amount of span 80, and the cross-linker concentration were assessed on FB release profiles. In vitro release studies displayed a two-stage release behaviour with a fast initial release of the FB, followed by sustained and extended release, and the incorporation of GO into the CS Nps made the FB release more sustained and controlled manner. Besides, the cytotoxicity test of the FB-loaded CS-GO Nps was studied through MTT assay, and it was found that they were biocompatible. Based on these findings, it can be inferred that the prepared CS-GO Nps might be a promising candidate drug carrier system for FB.

Propolis Controlled Delivery Systems for Oral Therapeutics in Dental Medicine: A Systematic Review.

This systematic review synthesizes the existing evidence in the literature regarding the association of propolis with controlled delivery systems (DDSs) and its potential therapeutic action in dental medicine. Two independent reviewers performed a literature search up to 1 June 2023 in five databases: PubMed/Medline, Web of Science, Cochrane Library, Scopus, and Embase, to identify the eligible studies. Clinical, in situ, and in vitro studies that investigated the incorporation of propolis as the main agent in DDSs for dental medicine were included in this study. Review articles, clinical cases, theses, dissertations, conference abstracts, and studies that had no application in dentistry were excluded. A total of 2019 records were initially identified. After carefully examining 21 full-text articles, 12 in vitro studies, 4 clinical, 1 animal model, and 3 in vivo and in vitro studies were included (n = 21). Relevant data were extracted from the included studies and analyzed qualitatively. The use of propolis has been reported in cariology, endodontics, periodontics, stomatology, and dental implants. Propolis has shown non-cytotoxic, osteoinductive, antimicrobial, and anti-inflammatory properties. Moreover, propolis can be released from DDS for prolonged periods, presenting biocompatibility, safety, and potential advantage for applications in dental medicine.

Novel Natrosol/Pectin-co-poly (acrylate) based pH-responsive polymeric carrier system for controlled delivery of Tapentadol Hydrochloride

Background & ObjectivesThis study aimed to create a controlled delivery system for Tapentadol Hydrochloride by developing interpenetrating networks (IPNs) of Natrosol-Pectin copolymerized with Acrylic Acid and Methylene bisacrylamide, and to analyze the effects of various ingredients on the physical and chemical characteristics of the IPNs. MethodsNovel Tapentadol Hydrochloride-loaded Natrosol-Pectin based IPNs were formulated by using the free radical polymerization technique. Co-polymerization of Acrylic Acid (AA) with Natrosol and Pectin was performed by using Methylene bisacrylamide (MBA). Ammonium persulfate (APS) was used as the initiator of crosslinking process. The impact of ingredients i.e. Natrosol, Pectin, MBA, and Acrylic Acid on the gel fraction, porosity, swelling (%), drug loading, and drug release was investigated. FTIR, DSC, TGA, SEM and EDX studies were conducted to confirm the grafting of polymers and to evaluate the thermal stability and surface morphology of the developed IPNs. ResultsSwelling studies exhibited an increase in swelling percentage from 84.27 to 91.17% upon increasing polymer (Natrosol and Pectin) contents. An increase in MBA contents resulted in a decrease in swelling from 85 to 67.63%. Moreover, the swelling was also observed to increase with higher AA contents. Significant drug release was noted at higher pH instead of gastric pH value. Oral toxicological studies revealed the nontoxic and biocompatible nature of Natrosol-Pectin IPNs. Interpretation & ConclusionThe developed IPNs were found to be an excellent system for the controlled delivery of Tapentadol Hydrochloride.

Intrathecal drug delivery systems for cancer pain control: Insights on current contemporary practices in the US.

6605 Background: About a third of cancer survivors report moderate to severe pain. Intrathecal drug delivery system (IDDS) is an implantable pain control option for treating intractable chronic pain not responsive to systemic opioid therapy. Studies on the current practices in the US around the utilization of IDDS for cancer pain are lacking. Methods: The Nationwide inpatient sample (NIS) dataset is funded by the Agency for healthcare research and quality (AHRQ) for multistate healthcare research & decision-making. Adult patients admitted to hospitals with a primary or secondary cancer diagnosis between 2016-19 were included. Patients undergoing IDDS implantation were identified using the validated International Classification of Diseases, 10th Revision, Procedure Coding System codes (00HU33Z Insertion of infusion device into spinal canal, percutaneous approach and 0JH80VZ Insertion of infusion pump into abdomen subcutaneous tissue and fascia, open). Baseline demographics, hospital characteristics, and type of cancer associated with IDDS implantation were evaluated in the study. Results: 22,895 patients underwent IDDS surgery amongst 7.06 million hospitalizations from 2016-19. The IDDS cohort consisted of patients in the 65-79 years age group (40.49%), female sex (50.42%), and Caucasian ethnicity (75.82%). Most IDDS surgeries were performed in large, urban teaching hospitals. Conclusions: Despite recommendations supporting IDDS use, a small minority received the treatment with significant racial & socioeconomic disparities in IDDS use. [Table: see text]

Nanopesticides: Promising Future in Sustainable Pest Management

Insects form the most successful and diverse group of animals present on earth today. Humans have shared a complex relationship with the insects. Though insects are indispensable as pollinators of crops yet at the same time they act as major destroyer of grains, pulses and fruits in the fields along with their post- harvest storage. Many of the dreadful diseases are also being transmitted by insect vectors to humans, livestock and other animals. Economic damage caused by insect pests is enormous. Adoption of advanced pest management strategies can alleviate the monetary losses substantially. Nanotechnological approach for pest control is an emerging and effective technique since it encompasses a wide range of objectives of an efficient pesticide like increased dispersion and solubility, slow release, controlled delivery system and protection against degradation. Newer formulations of pesticides with the intervention of nanotechnology are aimed to enhance their pesticidal properties. Insecticide formulations using nanomaterials as carriers of active ingredient have shown promising results for mitigation of pests of agriculture, storage and disease vectors. However, at present the knowledge is limited. There is a need for extensive evaluation of the toxicity of nanopesticides and the risks involved for humans and environment before their large-scale production and adoption.
 In this review article nanoformulations of pesticides with special emphasis on metal-based nanopesticides and their role as efficient alternatives in sustainable control of insect pests without much adverse impact on the environment has been summarized.

Preparation of Molecularly Imprinted Hydrogel Contact Lenses for Extended Atropine Eluting

The prevalence of myopia is becoming the primary public health issue globally. Low-concentration atropine showed a significant effect in controlling myopia progression. However, the dosage form of eye drops presents <5% ocular bioavailability and burst release. In this work, a series of molecularly imprinted hydrogel (MIP) contact lenses with different functional comonomers were prepared for atropine delivery, with non-imprinted hydrogel (NIP) contact lenses being fabricated for control. Key contact lens properties (including light transmission, water content, and surface wettability) and drug loading/release behavior were evaluated. According to our results, specific MIP adsorption onto atropine promoted drug loading capability while regulating drug release in contact lenses. By using methacrylic acid (MAA) and methacrylamide (MAm) to be the functional comonomers, the imprinted hydrogel (MIP-2) was most affiliative for atropine, which could delay in vitro drug release time up to 72 h, without affecting key properties of contact lenses. The cytotoxicity study indicated the good biocompatibility of MIPs, revealing their great potential as efficient ocular drug delivery systems for myopia control.

Programmably Controllable Delivery of Metastable Ferrous Ions for Multiscale Dynamic Imaging Guided Photothermal Primed Chemodynamic Therapy.

Metallomodulation cell death strategies are extensively investigated for antitumor therapy, such as cuproptosis, ferroptosis, and chemodynamic therapy (CDT). Undoubtedly, the accurate and specific elevation of metal ions levels in cancer cells is key to boosting theirtherapeutic index. Herein, a programmably controllable delivery system based on croconium dye (Croc)-ferrous ion (Fe2+ ) nanoprobes (CFNPs) is developed for multiscale dynamic imaging guided photothermal primed CDT. The Croc, with kinds of electron-rich iron-chelating groups, can form the Croc-Fe2+ complex with a precise stoichiometry of 1:1 to steadily maintain the valence state of Fe2+ . The CFNPs can achieve pH-responsive visualization and accurate Fe2+ release in cancerous tissues under the coactivation of "dual-key" stimulation of "acidity and near-infrared (NIR) light". The acidic tumor microenvironment actuates NIR fluorescence/photoacoustic imaging and photothermal properties of CFNPs. Sequentially, under exogenous NIR light, the CFNPs enable in vivo accurate visualization of Croc-Fe2+ complex delivery for photothermal primed Fe2+ release, thus achieving CDT of tumors. By leveraging multiscale dynamic imaging technologies, the complicated spatiotemporal release of Fe2+ is sketched in a programmably controllable manner, and the domino effect of tumor pH level, photothermal effect, and CDT is also revealed, endowing customized feedback of the therapeutic panorama within the disease microenvironment.

Evaluating Immobilization of Hemoglobin onto Nanomesoporous MCM-41

Introduction: The development and applications of biological products have been seriously hindered by conventional immobilization for its low efficiency and high cost. The immobilization on solid supports for enzyme is an area of intense research due to their widespread use in synthetic chemistry and various industries. This paper highlights a great interest in the adsorption of an enzyme on the solid porous structured material and the design of new controlled delivery systems. The enzyme immobilized on solid supports and synthetic materials of the reaction mixture with strong mechanical force and easy separation serves as a high selective catalyst. Objective: A novel protein delivery system for hemoglobin (Hb) enzyme was proposed by incorporating the molecular molecules into the mesopores of well-ordered hexagonal nanometer MCM (Mobil Composition of Matters) - 41. The prepared adsorbents were successfully applied to the design and synthesis of new functionalization materials. Various parameters affecting adsorption process, such as adsorption time, adsorption isotherm, and the reusability of adsorbent, were investigated. Methods: The interaction between Hb and MCM-41 was investigated using powder X-ray diffraction (XRD), Fourier infrared spectroscopy, UV-visible solid diffuse reflectance spectroscopy and 77 K lowtemperature N2 adsorption-desorption study. Results: The experimental parameters were optimized, including the concentrations of Hb, the MCM-41 amount, and the interior surface of phenyl-functionalized Ph-MCM-41 materials. Under the optimized conditions, the biocatalytic performance was studied for Hb/MCM-41 and Hb/Ph-(MCM-41). The adsorption process of Hb by MCM-41 / Ph-(MCM-41) was in agreement with the quasi-two-order kinetic model. Process of Hb adsorption by MCM-41 / Ph-(MCM-41) belongs to an exothermic reaction, the reaction is not reversible at 4°C and it is a spontaneous reaction. The Freundlich model can better describe the adsorption of hemoglobin on MCM-41 / Ph-(MCM-41). During the desorption process of composite (MCM-41)-Hb/[Ph-(MCM-41)]-Hb in 0.1 mol/L NaOH solution, the desorption rate can reach above 70% at 2 min. At 60 min, the desorption reached equilibrium and the desorption rates were 99.58% and 91.36%, respectively. The reuse activity experimental results indicated that the immobilized enzyme exhibited high catalytic activity. Reusability stability studies suggested that the prepared composites retained their activity even after five recycling runs. This shows that the phenylation of MCM-41 reduced the "leakage" of enzyme in the main material. Conclusion: The results of the present study demonstrated that Hb/MCM-41 and Hb/Ph-(MCM-41) are highly efficient potential nanobiocatalysts for the immobilization of enzymes onto mesoporous materials.

Review: Therapetic Approach in the Management of Osteoarthritis

Objectives: The goal in designing sustained or controlled delivery systems is to reduce the frequency of dosing or to increase the effectiveness of the drug by localization at the site of action, reducing the dose required, and providing uniform drug delivery. A sustained release system is a type of modified drug delivery system that can be used as an alternative to a conventional drug delivery system.
 Summary: Osteoarthritis is a generative disease of synovial joints characterized by focal loss of articular hyaline cartilage with the proliferation of new bones and remodelling of joint contour. Risk factors of osteoarthritis are age, female gender, joint alignment, hereditary gene defect, joint injury and obesity.There are various symptoms of osteoarthritis and It diagnose by blood test, joint fluid test and MRI. Osteoarthritis is treated by self-care, medications, therapies, and surgeries. A sustained-release dosage form is a dosage form that maintains the therapeutic blood or tissue levels of the drug by continuous release of medication. Formulation of granules by wet granulation and the granules are evaluated by the pre-compression and post-compression studies.
 Conclusion: Sustained release tablet optimize drug release for extended time period.It maximized effectiveness, reduced side-effects of drug and cures the disease.

Study on the Minimum Fire-Extinguishing Concentration of Several Commonly Used Extinguishing Agents to Suppress Pyrolysis Gas of Red Pine Wood.

The suppression of forest wood burning has been one of the important research directions in the field of solid combustible fire safety. The process of forest wood flame propagation is a coupled process of solid-phase pyrolysis and gas-phase combustion chemical reactions; therefore, as long as the solid-phase pyrolysis or gas-phase combustion can be suppressed, the forest wood flame propagation can be suppressed and an important contribution can be made to the subsequent suppression of forest wood fires. Previous studies have focused on the inhibition of solid-phase pyrolysis of forest wood, so this paper examines the effectiveness of several common fire suppressants for suppressing forest wood gas-phase flames, starting with the inhibition of forest wood gas-phase combustion. In this paper, for the convenience of the study, we narrowed the scope of the research object to the previous research ideas for gas fires, established a simplified small-scale flame model for forest wood fire suppression, took red pine wood as the research object, analyzed the pyrolysis gas components after high-temperature pyrolysis, and constructed a Cup burner suitable for N2, CO2, fine water mist, and NH4H2PO4 powder to extinguish the pyrolysis gas flame of red pine wood, respectively. The experimental system, together with the 9306 fogging system and the improved powder delivery control system, shows the process of extinguishing fuel flames such as red pine pyrolysis gas at 350, 450, and 550 °C with various types of fire-extinguishing agents on this device. It was found that the flame morphology was related to the composition of the gas and the type of extinguishing agent. At the same time, NH4H2PO4 powder appeared to burn above the cup mouth when pyrolysis gas interacted with it at 450 °C, but this phenomenon did not occur when other extinguishing agents interacted with it and only appeared when pyrolysis gas interacted with it at 450 °C, so it was judged that this phenomenon was related to the CO2 content of the gas component and the type of extinguishing agent. The study found that the four extinguishing agents extinguish red pine pyrolysis gas flame MEC value. There's a big difference. The worst performance is N2. Compared with N2 suppression of red pine pyrolysis gas flame, CO2 suppression effectiveness is 60% higher, but compared to the suppression effectiveness of fine water mist and far away, the suppression effectiveness of fine water mist is much higher than the suppression effectiveness of CO2. However, the difference in effectiveness between fine water mist and NH4H2PO4 powder is almost double. In summary, in the suppression of red pine gas-phase flame, four kinds of fire-extinguishing agents are ranked as follows: N2 < CO2 < fine water mist < NH4H2PO4 powder. Finally, the suppression mechanism of each type of extinguishing agent was analyzed. The study of this paper can provide some data to support the extinguishing of open fires in forest fires or suppressing the rate of forest fire spread.

Pharmaceutical/Clinical Strategies in the Treatment of Acute Promyelocytic Leukemia: All-Trans Retinoic Acid Encapsulation by Spray-Drying Technology as an Innovative Approach-Comprehensive Overview.

Acute promyelocytic leukemia (APL) is phenotypically characterized by the accumulation of dysplastic promyelocytes, resulting from a cytogenetic condition due to the balanced chromosomal translocation t(15;17)(q22;q21). Current first-line treatment of APL includes all-trans retinoic acid (all-trans RA), with or without arsenic trioxide, combined with chemotherapy, and a chemotherapy-free approach wherein arsenic trioxide is used alone or in combination with all-trans RA. The usage of all-trans RA revolutionized the treatment of APL, with survival rates of 80 to 90% being achieved. The mechanism of action of all-trans RA is based on regulation of gene transcription, promoting the differentiation of leukemic promyelocytes. Encapsulation technology has been explored as an innovative strategy to overcome the major drawbacks related to the all-trans RA oral administration in the APL treatment. The most recently published works on this subject highlight the development and optimization of carrier-based delivery systems based in microparticle formulations obtained by spray-drying to be used in the treatment of APL. The ultimate goal is to obtain a controlled delivery system for RA oral administration capable of providing a slow release of this bioactive compound in the intestinal lumen.

Microbial cellulosic pad encompassing alpha-arbutin in Tragacanth gum as the controlled delivery system

This research focuses on preparing a natural-based drug delivery system for α-arbutin (AR) as a skin lightening. Bacterial cellulose nanofibers (BC) pad was used for controlled-AR release through two approaches. First was the dip-drying method (P-BC), in which AR cross-linked to BC pads using citric acid (CA). The second was simultaneously entrapping of AR in Tragacanth gum (AR-TG) and stabilized on BC (BC-T) through the ultrasonic-assisted microemulsion method. UV–Vis spectra revealed better control of AR release in BC-T in the first hour. High cell viability (above 70 %) of the pads containing 1–3 % AR was reported using MTT assay. The in-vitro permeation study indicated the proper AR penetration in the treated pads. The Fickian diffusion model was determined as a fitted model for all pads in the drug release kinetics. FTIR, XRD, and TGA analyses further characterized the pads. FESEM images verified AR-TG and BC structures with average diameters of 410.7 ± 25.4 and 34.5 ± 7.51 nm, respectively. The hydrophilicity and mechanical properties of the pads were also investigated. Finally, the high biocompatibility, initial controlled release, and proper permeation suggested BC-T as a more promising delivery platform for AR.

Development of controlled delivery systems by nanoliposomes of Hypericum perforatum L. extracts

Development of controlled delivery systems by nanoliposomes of Hypericum perforatum L. extracts

Experimental study of flame extinguishing of red pine wood pyrolysis gas by NH4H2PO4 powder based on Cup-burner

Suppression of forest fires has been one of the important research directions in the field of fire safety, ammonium phosphate and its mixture of inhibitors commonly used in solid combustible fires, for forest fire scenarios, also has a good fire suppression effectiveness, inexpensive and easy to store, but also the current suppression of forest fires is one of the main inhibitors. However, there are few studies on the interaction between ammonium phosphate and forest fires. In this paper, to facilitate the study, we enter the previous research ideas for gas fires, reduce the scale of the research object, establish a small-sized simplified flame model for suppressing wood fires, take red pine wood as the research object, analyze the pyrolysis gas components after high-temperature pyrolysis, and construct the Cup-burner experimental system, together with an improved powder delivery control system, so that the process of NH4H2PO4 powder quenching fuel flames such as red pine pyrolysis gas at 350 °C, 450 °C and 550 °C was well presented on this device. It was found that the flame morphology was not only related to the gas composition but also the amount of NH4H2PO4 powder added and the particle size; the Minimum fire extinguishing concentration(MEC) value was not only related to the gas composition but also the particle size of NH4H2PO4 powder. This is because the CO2 content decreases and the H2 and CH4 content increase significantly in the gas composition at 550 °C compared to the 450 °C gas composition. Among the same pyrolysis gas components, the MEC value gradually increased as the particle size of NH4H2PO4 powder decreased, and the MEC value of 30 μm–40μm particle size powder was the lowest, and the difference between the particle size MEC value and the other two particle sizes was large, while the difference between the MEC values of 20 μm–30μm particle size powder and 10 μm–20μm particle size powder was small; according to the Cup-burner test The chemical thermodynamic analysis was carried out according to the results of the Cup-burner test to obtain the proportion of NH4H2PO4 powders playing a physical role in fire extinguishing. When NH4H2PO4 powder is involved in syngas/air combustion, the end product is P2O5 and xsp = 2.35%. When the end product is HPO3, xsp = 7.29%. The products were collected after the interaction of NH4H2PO4 powder with the synthesis gas flame, and the analysis of the products revealed that the products were sticky and not dry solids, and the material analysis of them revealed that they contained more HPO3 and its mixture, which shows that the physical heat absorption played a greater role when NH4H2PO4 powder interacted with the synthesis gas flame.

Therapeutic Potential of Controlled Delivery Systems in Asthma: Preclinical Development of Flavonoid-Based Treatments.

Asthma is a chronic disease with increasing prevalence and incidence, manifested by allergic inflammatory reactions, and is life-threatening for patients with severe disease. Repetitive challenges with the allergens and limitation of treatment efficacy greatly dampens successful management of asthma. The adverse events related to several drugs currently used, such as corticosteroids and β-agonists, and the low rigorous adherence to preconized protocols likely compromises a more assertive therapy. Flavonoids represent a class of natural compounds with extraordinary antioxidant and anti-inflammatory properties, with their potential benefits already demonstrated for several diseases, including asthma. Advanced technology has been used in the pharmaceutical field to improve the efficacy and safety of drugs. Notably, there is also an increasing interest for the application of these techniques using natural products as active molecules. Flavones, flavonols, flavanones, and chalcones are examples of flavonoid compounds that were tested in controlled delivery systems for asthma treatment, and which achieved better treatment results in comparison to their free forms. This review aims to provide a comprehensive understanding of the development of novel controlled delivery systems to enhance the therapeutic potential of flavonoids as active molecules for asthma treatment.

Transport properties of hydrophilic compounds in PLGA microspheres

Biodegradable polyesters, such as the poly(lactic-co-glycolic acid) (PLGA), have been extensively used as a polymer matrix for entrapping a variety of active compounds. In this study, the physicochemical phenomena that control the mass transport mechanism of hydrophilic compounds released from PLGA microspheres were identified. This study aims to produce and characterize PLGA microspheres loaded with metformin hydrochloride (MH) and perform a case study using the literature data of PLGA microspheres loaded with fluorescein isothiocyanate-dextran (FITC-dextran). The MH is a low molecular weight compound that was easily and rapidly transported by diffusion mechanism through the microsphere pores. The FITC-dextran, as a high molecular weight compound, depended on the mechanism of polymer erosion and mesopore formation, with 18 days of duration, before its release by diffusion mass transfer. Values of the effective diffusion coefficient of MH and FITC-dextran, both in PLGA, were 2.4 x 10-13 and 5.3 x 10-18 m2 s-1, respectively, with a difference of five orders of magnitude attributed to the molecular weight of these hydrophilic compounds and the main mass transport that governed their release. This study provides important insights into the mechanisms of mass transfer and their correlation with the physicochemical properties of both hydrophilic compounds and the PLGA matrix, contributing to the development of biodegradable controlled delivery systems for a variety of applications in chemical, biotechnological, and pharmaceutical industries.

Producing mixed-soy protein adsorption layers on alginate microgels to controlled-release β-carotene

In this study, the effects of soy protein isolate (SPI) on the morphology, encapsulation efficiency, storage stability, swelling behavior, and in vitro digestion behavior of calcium alginate (CA) microgels were investigated. CA and calcium alginate-SPI (CAS) microgels with encapsulated β-carotene were prepared by extruding a mixture of alginate and SPI using a co-extrusion technique, followed by cross-linking with Ca2+. All microgels exhibited homogeneous sizes and spherical shapes, and CAS microgels showed high levels of protein loading efficiency. The encapsulation efficiency and storage stability of β-carotene within CAS microgels were higher than those within CA microgels. The introduction of SPI into CAS microgels resulted in a higher degree of gel size shrinkage in gastric fluid and a lower degree of swelling in intestinal fluid compared to CA microgels. In vitro digestion was conducted to investigate the effects of the addition of SPI on the release behavior of CA and CAS microgels. Results obtained showed that CAS microgels were more resistant to simulated gastric fluid than CA microgels. Cryo-scanning electron microscopy (cryo-SEM) and confocal laser scanning microscopy (CLSM) observations indicated that the release behavior was dependent on the porosity of the CA and CAS microgels, and the porosity was influenced by the concentration of SPI. This study showed that the introduction of SPI to CA microgels can lead to the development of an effective controlled release delivery system.

Designing Starch–Alginate Hydrogels for Controlled Delivery of Fungicide for the Alleviation of Environmental Pollution

In this work, a controlled delivery system for the fungicide thiophanate-methyl (TM) was developed for the alleviation of environmental pollution using starch–alginate–polyacrylamide hydrogels as a sustainable agricultural development approach. The polymer hydrogel was synthesized by grafting poly(acrylamide) onto starch–alginate using N,N-methylenebisacrylamide (NNMBA) as the cross-linker. The copolymers were confirmed by characterization techniques including scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared analysis, X-ray diffraction, 13C NMR, TGA-DTG, and differential scanning calorimetry. SEM confirmed the heterogeneity, and AFM showed the rough surface morphology of the copolymeric hydrogels. The thermogravimetric analysis results indicated the increase in the thermal stability of the cross-linked polymers after modification. Evaluation was carried out on the water absorption capacity of the polymer and the release of the encapsulated fungicide. The swelling of the hydrogel decreased with the increment in cross-linking density with a rise in [NNMBA]. It also influenced the diffusion of the fungicide from the encapsulated copolymer, wherein the increase in the cross-linker content decreased the fungicide release from the copolymer. Hydrogels absorbed 18.30 ± 1.40 (g/g of gel) water, indicating the water retention capacity of the hydrogel material which could be useful for plant growth in the arid regions. The release profile followed the non-Fickian diffusion mechanism with a sustained delivery of TM. Water retention and the controlled release properties of the hydrogel indicated its usefulness in sustainable agricultural development and alleviation of environmental pollution caused by the fungicide use. Overall, the formation of a controlled pesticide delivery system based on natural polysaccharides with polyacrylamide-based hydrogels which act as nutrients for plants on degradation is a unique approach, implying that the slow release of the pesticide will reduce environmental pollution and pesticide cost.

Development of polymeric nanofibers blended with extract of neem (Azadirachta indica), for potential biomedical applications

In recent years, electrospinning has emerged as a promising technique for the preparation of nanofibers with unique properties like flexibility, high porosity and high surface area. In the context of nanodelivery systems, polymer-based nanofibers have become promising carriers of drugs and bioactive compounds ensuring their sustained release and targeted delivery. In this study, neem extract-loaded nanofibers were developed as sustained delivery systems using the electrospinning method. The chitosan, alginate and polyethylene oxide were used as the polymeric matrix for loading of aqueous extract of neem leaves. The prepared nanofibers NF1, NF2 and NF3 carrying 2%, 4% and 6% extract respectively were characterized using SEM, FTIR, XRD and TGA. Further, the as-prepared nanocomposites exhibited a high degree of swelling and dual-phase release of phytoconstituents. Moreover, the developed controlled delivery systems were tested for antifungal and antioxidant potential. Importantly, the bioactivities of the prepared nanofibers could be improved further by using organic extracts which are generally enriched with phytoconstituents. Herein, we selected biodegradable and mucoadhesive biopolymers and an aqueous extract of neem for the development of controlled-delivery nanofibers by electrospinning through a sustainable and cleaner production process. Thus, the prepared biocompatible nanofibrous systems with biphasic release profile could be employed for biomedical applications including wound dressing, soft tissue scaffolds and as transdermal carriers.

Preparation and characterization of benzydamine hydrochloride-loaded lyophilized mucoadhesive wafers for the treatment of oral mucositis

Chemo/radiotherapy-induced oral mucositis (OM) has painful ulcers that can impair patients' lives. This study aimed to develop and characterize (in vitro and in vivo) benzydamine (BNZ) freeze-dried mucoadhesive wafers from chitosan (CS) in combination with different hydrophilic polymers as a locally controlled delivery system for OM treatment. The porous (69–83%) optimum wafers (0.02–0.03 g and 3.2–4.3 mm) released 90–95% of their drug content over 8 h and demonstrated 40–53 g mucoadhesion strength. Mechanical evaluations of F1 (CS) and F14 (CS/HPMC (3:1)) selected formulations showed modulus of elasticity, tensile strength, and % elongation at break ranging from 0.2 to 0.3 MPa, 0.01–0.02 MPa, and 15–18%, respectively. The antimicrobial efficacy of BNZ-loaded wafers was significantly higher than drug-free ones. The extract solutions of the drug-free and BNZ-loaded wafers revealed 100 and 20% viability in human gingival fibroblasts (HGFs) exposure. In vivo analysis demonstrated that BNZ-loaded wafers represented a significant reduction in macroscopic evaluation of OM and histopathological tests compared to positive and negative controls and drug-free wafers. Conclusively, lyophilized F1 and F14 mucoadhesive wafers had acceptable structural, mechanical, and biological properties and might be promising drug delivery systems for OM.