Effect of degree of cross-linking on swelling and drug release behaviour of poly(methyl methacrylate-co-itaconic acid) [P(MMA/IA)] hydrogels for site specific drug delivery

Formulation and In Vitro Assessment of Polymeric pH-Responsive Nanogels of Chitosan for Sustained Delivery of Madecassoside

Madecassoside, a triterpenoid saponin compound mainly isolated from the gotu kola herb (Centella asiatica), shows an extensive range of biological activities, including antiapoptotic, antioxidant, anti-inflammatory, moisturizing, neuroprotective, and wound healing effects. It has been highly used in the management of eczema, skin wounds, and other diseases. Due to poor oral bioavailability, membrane permeability, and intestinal absorption, the clinical application of the madecassoside is limited. Hence, a drug carrier system is needed that not only sustains the release of the madecassoside but also overcomes the drawbacks associated with its administration. Therefore, the authors prepared novel pH-responsive chitosan-based nanogels for the sustained release of madecassoside. Free radical polymerization technique was used for cross-linking of polymer chitosan and monomer methacrylic acid in the presence of cross-linker N',N'-methylene bis(acrylamide). The decrease in polymer crystallinity after polymerization and development of nanogels was demonstrated by XRD and FTIR analysis. The effects of nanogel contents on polymer volume, sol-gel analysis, swelling, drug loading, and release were investigated. Results indicated that high swelling and maximum release of the drug occurred at pH 7.4 compared to pH 1.2 and 4.6, indicating the excellent pH-sensitive nature of the engineered nanogels. High swelling and drug release were perceived with the integration of a high quantity of chitosan, while a decline was observed with the high integration of N',N'-methylene bis(acrylamide) and methacrylic acid contents. The same effects of nanogel contents were shown for drug loading too. Sol fraction was reduced, while gel fraction was enhanced by increasing the chitosan load, N',N'-methylene bis(acrylamide), and methacrylic acid. The Korsmeyer-Peppas model of kinetics was trailed by all nanogel formulations with non-Fickian diffusion. The results demonstrated that prepared nanogels can be employed for sustained release of the madecassoside.

Oncolytic Virotherapy: An Advanced Microbial Approach for the Management of Cancer

Destruction of the tumor (cancerous) cells may be caused by live viruses, which have replicative ability and replicate selectively in tumor cells, known as oncolytic virotherapy. In comparison of conservative cancer therapy, tumor-selective replicating viruses have more advantages. These viruses have introduced new methodologies for the human cancer treatment. Numerous strategies are used in development of virotherapeutics. Virotherapy is not unusual concept, but modern advances in technology of genetic modification of oncolytic viruses have improved the ability of targeting tumor cells more specifically, it triggered the development of novel ammunition to fight cancer. An effective virotherapeutic approach with oncolytic viruses exhibits the feasibility and safety under clinical approach. New strategies are being explored to overcome basic obstacles and challenges in virotherapy. Administration of oncolytic viruses, logically, will successfully augment new treatments against many kinds of tumors. Some encouraging antitumor responses shown by combination therapy are provoking strong immunity against established cancer. Chief developments in oncolytic virotherapy have seen in past several years. Significant understandings have been provided by findings on the interface among immune comebacks and viruses, whereas potential results have shown in clinical trials.

Efficacy and Nuances of Precision Molecular Engineering for Hodgkin's Disease to a Gene Therapeutic Approach

Gene therapy is a particularly useful treatment for nervous system genetic diseases, including those induced especially by infectious organisms and antigens, and is being utilized to treat Hodgkin's disease (HD). Due to the possible clonal relationship between both disorders, immunotherapy directed against CD20 positive cells may be a more effective treatment in patients with persistent HD and NHL. HL growth can be inhibited both in vitro and in vivo by AdsIL-13Ralpha2. High-dose treatment combined with stem cell transplantation has been effective in treating HIV-negative lymphoma that has progressed to high-risk or relapsed disease. For therapy, LMP2-specific CTL will be used. Furthermore, it is possible to view the cytotoxicity of genetically modified adenoviruses that express proteins such as p27Kip1, p21Waf1, and p16INK4A as a foundational element for (2,5)-derived ALCL genetic treatment for Hodgkin's disease.

Advances in the Management of Neuroblastoma

Neuroblastoma is a malignant tumor of neuroblasts, immature nerve cells found in several areas of the body. It usually affects children under age of 5. As usual, the tumor has ability to grow rapidly and to expand vastly which ultimately leads to death. Mostly, management decisions can be drawn by the prediction of the stage of the disease as well as age at the time of its diagnosis. There are four main stages of neuroblastoma, and treatment is according to the low and high risk of the disease. Several cytotoxic agents along with other therapies (antibody therapy, gene therapy, and even immunological therapies, antiangiogenic therapy, etc.) are used. Immunotherapy also has an important treatment option used nowadays for neuroblastoma. The discovery of major neuroblastoma-predisposition gene anaplastic lymphoma kinase cause somatic transformation or gene strengthening in diagnosed neuroblastoma. Promising new antiangiogenic strategies have also been introduced for the treatment of neuroblastoma with multiple mylomas. To manage numerous myelomas and cancers, including neuroblastoma, bone marrow transplantation and peripheral blood stem cell transplantation may be used.

Arboviruses: Transmission and Host Resistance

In this review, there is a complete description of the classes of arboviruses, their evolutionary process, virus characterization, disease transmission methods; it also describes about the vectors involved in transmission and their mood of transmission, both biologically as well as non-biologically and, about host, the resistance mechanism in host, and artificial methods of preventing those viral transmissions. Arboviruses transmitted to hosts by some vectors such as mosquitoes, ticks, etc. The virus replicates in the host can be prevented by some host resistance mechanisms like RNA interference (RNAi), which degrade virus RNA by its antiviral activity, insect repellents, IGRs, and PI technology.

Holistic Approach to Process Design and Scale-Up for Itaconic Acid Production from Crude Substrates

Bio-based bulk chemicals such as carboxylic acids continue to struggle to compete with their fossil counterparts on an economic basis. One possibility to improve the economic feasibility is the use of crude substrates in biorefineries. However, impurities in these substrates pose challenges in fermentation and purification, requiring interdisciplinary research. This work demonstrates a holistic approach to biorefinery process development, using itaconic acid production on thick juice based on sugar beets with Ustilago sp. as an example. A conceptual process design with data from artificially prepared solutions and literature data from fermentation on glucose guides the simultaneous development of the upstream and downstream processes up to a 100 L scale. Techno-economic analysis reveals substrate consumption as the main constituent of production costs and therefore, the product yield is the driver of process economics. Aligning pH-adjusting agents in the fermentation and the downstream process is a central lever for product recovery. Experiments show that fermentation can be transferred from glucose to thick juice by changing the feeding profile. In downstream processing, an additional decolorization step is necessary to remove impurities accompanying the crude substrate. Moreover, we observe an increased use of pH-adjusting agents compared to process simulations.

Preparation and Characterization of Poly(vinyl Acetate-co-2-hydroxyethyl Methacrylate) and In Vitro Application as Contact Lens for Acyclovir Delivery

A series of poly(vinyl acetate-co-2-hydroxyethylmethacrylate)/acyclovir drug carrier systems (HEMAVAC) containing different acyclovir contents was prepared through bulk free radical polymerization of 2-hydroxyethyl methacrylate with vinyl acetate (VAc) in presence of acyclovir (ACVR) as the drug using a LED lamp in presence of camphorquinone as the photoinitiator. The structure of the drug carrier system was confirmed by FTIR and 1HNMR analysis, and the uniform dispersion of the drug particles in the carrier was proved by DSC and XRD analysis. The study of the physico-chemical properties of the prepared materials, such as the transparency, swelling capacity, wettability and optical refraction, was carried out by UV–visible analysis, a swelling test and measurement of the contact angle and the refractive index, respectively. The elastic modulus and the yield strength of the wet prepared materials were examined by dynamic mechanical analysis. The cytotoxicity of the prepared materials and cell adhesion on these systems were studied by LDH assay and the MTT test, respectively. The results obtained were comparable to those of standard lenses with a transparency of 76.90–89.51%, a swelling capacity of 42.23–81.80% by weight, a wettability of 75.95–89.04 o, a refractive index of 1.4301–1.4526 and a modulus of elasticity of 0.67–1.50 MPa, depending on the ACVR content. It was also shown that these materials exhibit no significant cytotoxicity; on the other hand, they show significant cell adhesion. The in vitro dynamic release of ACVR in water revealed that the HEMAVAC drug carrier can consistently deliver uniformly adequate amounts of ACVR (5.04–36 wt%) over a long period (7 days) in two steps. It was also found that the solubility of ACVR obtained from the release process was improved by 1.4 times that obtained by direct solubility of the drug in powder form at the same temperature.

AIDS Dementia Complex: Neurotoxicity in AIDS Patients

AIDS dementia complex (ADC) is a nervous system disorder that harms the neurons in different parts of the brain. Various features are involved in altering the normal activities of neurons. Neurotoxicity is induced due to HIV viral proteins such as gp120, SDF, Tat, etc. These proteins target macrophages, glial cells, astrocytes, and release neurotoxins. These neurotoxins proved harmful for the neurons, caused apoptotic cell death by raising calcium, glutamate level and by producing various free radicals such as nitric oxide (NO·). Lipid peroxidation and lipids rafts also play a vital role in producing toxicity and apoptotic cell death. Membrane associated oxidative stress, cognitive impairment, and high level of HNE (4-hydroxynonenal); all are involved in ADC pathogenesis.

Human Oropharyngeal Candidiasis: From Etiology to Current Treatment

Oral candidiasis is a common but most harmful oral cavity infection caused by yeast-like fungus, this condition is called Oropharyngeal candidiasis. There are various species of candida that are responsible for oral cavity fungal infection including mostly Candida albicans. Different candida infections may be acute and chronic. Cell-mediated immunity, humoral immunity, and granulocytes are the immune factors for the cause of this infection. Different antifungal drugs like nystatin, fluconazole, and amphotericin are used to treat oral cavity fungal infections.

In-vitro and in-vivo evaluation of biocompatible polymeric microgels for pH- driven delivery of Ketorolac tromethamine

The aim of the current study was to prepare glutamic acid crosslinked poly(itaconic acid/methacrylic acid) microgels for pH-responsive delivery of ketorolac tromethamine, using aqueous free radical polymerization technique. The polymerization of polymer with monomers was carried out by a crosslinking agent N', N'-methylene bisacrylamide in the presence of initiator ammonium persulfate. The prepared microgels were characterized for structure, surface morphology, thermal stability, and crystallinity. Similarly, studies such as sol-gel analysis, drug loading, and polymer volume fraction were performed for the fabricated microgels. The pH-sensitivity of the developed microgels was investigated at three different pH values i.e., pH 1.2, 4.6, and 7.4 by swelling and in-vitro drug release studies. Maximum swelling and drug release were found at pH 7.4 as compared to pH 1.2 and 4.6, which indicated the pH-sensitive nature of the prepared microgels. The toxicity of the prepared microgels was evaluated by cell line and HET-CAM test, which demonstrated no toxic effect of the prepared microgels. In-vivo study was carried out on rabbits and high plasma concentration was reported for the drug loaded microgels as compared to drug solution and commercial product Keten. Hence, the prepared microgel system could be employed as an excellent carrier for the controlled drug delivery system.

Formulation, Characterization, and In Vitro Drug Release Study of β-Cyclodextrin-Based Smart Hydrogels

In this study, novel pH-responsive polymeric β-cyclodextrin-graft-poly(acrylic acid/itaconic acid) hydrogels were fabricated by the free radical polymerization technique. Various concentrations of β-cyclodextrin, acrylic acid, and itaconic acid were crosslinked by ethylene glycol dimethacrylate in the presence of ammonium persulfate. The crosslinked hydrogels were used for the controlled delivery of theophylline. Loading of theophylline was conducted by the absorption and diffusion method. The fabricated network of hydrogel was evaluated by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffractometry (XRD), and scanning electron microscopy (SEM). The crosslinking among hydrogel contents and drug loading by the fabricated hydrogel were confirmed by FTIR analysis, while TGA indicated a high thermal stability of the prepared hydrogel as compared to pure β-cyclodextrin and itaconic acid. The high thermal stability of the developed hydrogel indicated an increase in the thermal stability of β-cyclodextrin and itaconic acid after crosslinking. Similarly, a decrease in crystallinity of β-cyclodextrin and itaconic acid was observed after crosslinking, as evaluated by XRD analysis. SEM revealed an irregular and hard surface of the prepared hydrogel, which may be correlated with strong crosslinking among hydrogel contents. Crosslinked insoluble and uncrosslinked soluble fractions of hydrogel were evaluated by sol–gel analysis. An increase in gel fraction was seen with the increase in compositions of hydrogel contents, while a decrease in sol fraction was observed. Dynamic swelling and dissolution studies were performed in three various buffer solutions of pH 1.2, 4.6, and 7.4, respectively. Maximum swelling and drug release were observed at higher pH values as compared to the lower pH value due to the deprotonation and protonation of functional groups of the hydrogel contents; thus, the pH-sensitive nature of the fabricated hydrogel was demonstrated. Likewise, water penetration capability and polymer volume were evaluated by porosity and polymer volume studies. Increased incorporation of β-cyclodextrin, acrylic acid, and itaconic acid led to an increase in swelling, drug release, drug loading, and porosity of the fabricated hydrogel, whereas a decrease was detected with the increasing concentration of ethylene glycol dimethacrylate. Conclusively, the prepared hydrogel could be employed as a suitable and promising carrier for the controlled release of theophylline.

Fabrication of alginate based microgels for drug-sustained release: In-vitro and in-vivo evaluation

The current study was conducted to evaluate and analyze the effect of alginate, itaconic acid, and N,N'-methylene bisacrylamide in formulation of a novel alginate based microgels for sustained release of theophylline. The fabricated microgels were characterized by PXRD, SEM, FTIR, TGA and DSC respectively. FTIR revealed that alginate reacted with itaconic acid during polymerization reaction and confirmed the overlapping of itaconic acid on the backbone of alginate. TGA and DSC depicted high thermal stability of the fabricated microgels as compared to pure unreacted polymer and monomer. Likewise, dynamic swelling and percent drug release studies were carried out at different pH media i.e., pH 1.2, 4.6 and 7.4 respectively. Greater dynamic swelling and percent drug release was observed at higher pH 7.4 as compared to lower pH 4.6 and 1.2 due to the deprotonation of COOH groups of both alginate and itaconic acid respectively. The drug release mechanism from the fabricated microgels could be described by first order model. In-vivo pharmacokinetic study was performed on rabbits and exhibited sustained release in rabbits. Hence, the developed microgels indicated higher potential as the delivery system for the sustained delivery of theophylline.

Synthesis, Characterization and Safety Evaluation of Sericin-Based Hydrogels for Controlled Delivery of Acyclovir

Conventional formulations of antiviral drug acyclovir have various limitations such as low bioavailability. The current study was aimed at developing polymeric matrices for the controlled delivery of acyclovir using sericin as polymer and acrylic acid (AA) as a monomer. The free radical polymerization technique was used for hydrogel formulation. Briefly, sericin was chemically cross-linked with acrylic acid. N′-N′-methylene bis-acrylamide (MBA) and ammonium persulfate (APS) were used as cross-linker and initiator, respectively. FTIR spectra showed that acyclovir was successfully loaded into sericin hydrogel. SEM micrographs revealed that the outer surface was solid-like and smooth. According to DSC thermograms, the developed polymeric network was thermally stable. Amorphous nature of acyclovir was observed in XRD. The pH of medium and reactants’ concentration affected swelling dynamics and acyclovir release pattern. In addition, drug release occurred through a diffusion-controlled process. Sericin hydrogel suspension was well tolerable up to 3800 mg/kg of rabbits’ body weight. Haematology and serum chemistry results were well within the range signifying normal liver and kidney functions. Similarly, histopathology slides of the rabbit’s vital organs were also in normal condition without causing any histopathological change. It was concluded from the findings that sericin-co-AA polymeric matrices are ideal for the pH-dependent delivery of acyclovir.

Dual drug delivery system based on pH-sensitive silk fibroin/alginate nanoparticles entrapped in PNIPAM hydrogel for treating severe infected burn wound

Herein, the pH-sensitive vancomycin (VANCO) loaded silk fibroin-sodium alginate nanoparticles (NPs) embedded in poly(N-isopropylacrylamide) (PNIPAM) hydrogel containing epidermal growth factor (EGF) are introduced for treating chronic burn wound infections. The hybrid system was developed to control the release rates of an antibiotic and growth factor for optimal treatment of burn infections. VANCO had a pH responsive release behavior from the nanoparticle (NP) and showed higher release rate in an alkaline pH compared to the neutral pH during 10 d. About 30% of EGF was also released from the hydrogel within 20 d. The released VANCO and EGF preserved their bioactivity more than ∼ 80%. The suitable physico-chemical properties and cellular behaviors of PNIPAM hydrogel supported the proliferation and growth of the fibroblast cells. Furthermore, the higher re-epithelialization with good wound contraction rate, neovascular formation, and expression of transforming growth factor-beta were observed in S. aureus infected rat burn wound by using the hydrogel containing VANCO and EGF compared with untreated wounds and hydrogel alone. The wound infection was also significantly reduced in the groups treated with the hydrogels containing VANCO. Overall, in vitro and in vivo results suggested that developed hybrid system would be a promising construct to treat severe wound infection.

Microwave-Assisted Synthesis of Cross-Linked Co-poly(itaconic anhydride-methyl methacrylate): The Effects of the Molar Ratio and Cross-Linking Agent on the Thermal Stability

In the present work, a new series of cross-linked copolymers based on itaconic anhydride and methyl methacrylate were prepared employing free radical copolymerization in the presence of azobisisobutyronitrile as an initiator and 2-butanone as a solvent under microwave irradiation. The copolymers containing itaconic anhydride (ITA) and methyl methacrylate (MMA) were chosen due to the formation of long-term stable anhydride moieties, which might be useful to attach enzymes covalently with numerous applications in water treatment. The copolymerization process was carried out in the presence of two types of cross-linking agent, namely, ethylene dimethacrylate (EDMA) and divinylbenzene (DVB) in a range of 0-20% (w/w) to explore their effect on the thermal and stiffness properties of the obtained cross-linked copolymers. Increasing the ratio of the cross-linking agent, the copolymers prefer to precipitate rather than form a gel during the polymerization process. While using ethylene dimethacrylate as a cross-linking agent, the copolymers change from porous to stiffness structures depending on the molar ratio of the monomers used during the polymerization. On the other hand, using divinylbenzene as a cross-linking agent, the stiffness structure was obtained in all cases and there is no effect observed for the monomer’s ratio or the percentage of cross-linking agent on the morphology of the prepared copolymers.

Integrated strain- and process design enable production of 220 g L-1 itaconic acid with Ustilago maydis

BACKGROUND

Itaconic acid is an unsaturated, dicarboxylic acid which finds a wide range of applications in the polymer industry and as a building block for fuels, solvents and pharmaceuticals. Currently, Aspergillus terreus is used for industrial production, with titers above 100 g L-1 depending on the conditions. Besides A. terreus, Ustilago maydis is also a promising itaconic acid production host due to its yeast-like morphology. Recent strain engineering efforts significantly increased the yield, titer and rate of production.

RESULTS

In this study, itaconate production by U. maydis was further increased by integrated strain- and process engineering. Next-generation itaconate hyper-producing strains were generated using CRISPR/Cas9 and FLP/FRT genome editing tools for gene deletion, promoter replacement, and overexpression of genes. The handling and morphology of this engineered strain were improved by deletion of fuz7, which is part of a regulatory cascade that governs morphology and pathogenicity. These strain modifications enabled the development of an efficient fermentation process with in situ product crystallization with CaCO3. This integrated approach resulted in a maximum itaconate titer of 220 g L-1, with a total acid titer of 248 g L-1, which is a significant improvement compared to best published itaconate titers reached with U. maydis and with A. terreus.

CONCLUSION

In this study, itaconic acid production could be enhanced significantly by morphological- and metabolic engineering in combination with process development, yielding the highest titer reported with any microorganism.

Phytotherapeutic potential and pharmaceutical impact of Phoenix dactylifera (date palm): current research and future prospects

Phoenix dactylifera (date palm) is a member of the genus Phoenix belonging to family Arecaceae. It is widely cultivated for its edible fruits and kernels. Dates have been used for both dietary purposes as well as for their phytomedicinal impacts against the variety of diseases. Date fruits are rich in alkaloids, protein, carbohydrate, fatty acid (linoleic, lauric, palmitic, and stearic acid), carotenoids, vitamins, polyphenolic compounds, flavonoids, and tannins along with different types of nutrients like potassium, calcium, magnesium, and phosphorus. Due to the presence of the variety of phytochemicals, they have greater impact on human health. They have strong antioxidant potential. It has been proposed now as a potential source of several unique medical and industrial products. In literature, much information is available on botanical descriptions, agriculture technology, and utilization in therapeutic intervention, but a little description is accessible on phytochemical relevance, formulation strategies, nutritional impact, and bioprocess technology. Therefore, the present review provides comprehensive information on the phytochemical relevance, pharmacology/bioactivity, pharmaceutical impact, their scope in bioprocess technology and nutraceutical values of date palm. According to all collected information, every portion of the plant has some beneficial properties that can serve as a source of medicine and nutraceutical.

Poly (2-hydroxyethylmethacrylate -co-methylmethacrylate)/Lignocaine Contact Lens Preparation, Characterization, and in vitro Release Dynamic

2-hydroxyethyl methacrylate, methylmethacrylate, ethylene glycol dimethyl methacrylate, and lignocaine (drug) were mixed together and the monomers were copolymerized at 60 °C through a free radical polymerization in the presence of α,α'-Azoisobutyronitrile in tetrahydrofuran. A series of copolymer/drug composites with different monoacrylate monomer compositions were prepared by solvent evaporation and characterized by different methods such as nuclear magnetic resonance, differential scanning calorimetry, Fourier transform infrared, X-ray diffraction, and mechanical and optical testing. The water content in the copolymers and the cell viability test on the samples were also examined in this investigation. The results of the analyses of the properties of this drug-carrier system are promising, indicating that this material may be a potential candidate for contact lens applications. The release dynamic of this medication from the prepared drug-carrier systems was investigated in neutral pH media. The results obtained revealed that the diffusion of lignocaine through the copolymer matrix obeys the Fick model and the dynamic release can be easily controlled by the methyl methacrylate content in the copolymer.

Microwave-Assisted Preparation of Hydrogel-Forming Microneedle Arrays for Transdermal Drug Delivery Applications

1A microwave (MW)-assisted crosslinking process to prepare hydrogel-forming microneedle (MN) arrays was evaluated. Conventionally, such MN arrays are prepared using processes that includes a thermal crosslinking step. Polymeric MN arrays were prepared using poly(methyl vinyl ether-alt-maleic acid) crosslinked by reaction with poly(ethylene glycol) over 24 h at 80 °C. Polymeric MN arrays were prepared to compare conventional process with the novel MW-assisted crosslinking method. Infrared spectroscopy was used to evaluate the crosslinking degree, evaluating the area of the carbonyl peaks (2000-1500 cm-1). It was shown that, by using the MW-assisted process, MN with a similar crosslinking degree to those prepared conventionally can be obtained in only 45 min. The effects of the crosslinking process on the properties of these materials were also evaluated. For this purpose swelling kinetics, mechanical characterisation, and insertion studies were performed. The results suggest that MN arrays prepared using the MW assisted process had equivalent properties to those prepared conventionally but can be produced 30 times faster. Finally, an in vitro caffeine permeation across excised porcine skin was performed using conventional and MW-prepared MN arrays. The release profiles obtained can be considered equivalent, delivering in both cases 3000-3500 μg of caffeine after 24 h.

Inhibitors of apoptotic proteins: new targets for anticancer therapy

Inhibitors of apoptotic proteins (IAPs) can play an important role in inhibiting apoptosis by exerting their negative action on caspases (apoptotic proteins). There are eight proteins in this family: NAIP/BIRC1/NLRB, cellular IAP1 (cIAP1)/human IAP2/BIRC2, cellular IAP2 (cIAP2)/human IAP1/BIRC3, X-linked IAP (XIAP)/BIRC4, survivin/BIRC5, baculoviral IAP repeat (BIR)-containing ubiquitin-conjugating enzyme/apollon/BIRC6, livin/melanoma-IAP (ML-IAP)/BIRC7/KIAP, and testis-specific IAP (Ts-IAP)/hILP-2/BIRC8. Deregulation of these inhibitors of apoptotic proteins (IAPs) may push cell toward cancer and neurodegenerative disorders. Inhibitors of apoptotic proteins (IAPs) may provide new target for anticancer therapy. Drugs may be developed that are inhibiting these IAPs to induce apoptosis in cancerous cells.