Biodegradable Dextrin-Based Microgels for Slow Release of Dual Fertilizers for Sustainable Agriculture.

In this research, we report dextrin-based biodegradable microgels (PDXE MGs) having phosphate-based cross-linking units for slow release of urea and a potential P source to improve fertilization. PDXE MGs (∼200 nm) are synthesized by cross-linking the lauroyl-functionalized dextrin chains with sodium tripolyphosphate. The developed PDXE MGs exhibit high loading (∼10%) and encapsulation efficiency (∼88%) for urea. It is observed that functionalization of PDXE MGs with lauroyl chains slows down the release of urea (90% in ∼24 days) as compared to nonfunctionalized microgels (PDX MGs) (99% in ∼17 days) in water. Further studies of the developed formulation display that Urea@PDXE MGs significantly boost maize seed germination and overall plant growth as compared to pure urea fertilizer. Moreover, analysis of maize leaves obtained from plants treated with Urea@PDXE MGs reveals 3.5 ± 0.3% nitrogen content and 90 ± 0.7 mg/g chlorophyll content. These values are significantly higher than 1.4 ± 0.6% nitrogen content and 48 ± 0.05 mg/g chlorophyll content obtained by using bare urea. Further, acid phosphatase activity in roots is reduced upon treatment with PDXE MGs and Urea@PDXE MGs, suggesting the availability of P upon degradation of PDXE MGs by the amylase enzyme in soil. These experimental results present the developed microgel-based biodegradable formulation with a slow release feature as a potential candidate to move toward sustainable agriculture practices.

Biodegradable redox sensitive chitosan based microgels for potential agriculture application.

In this work, we report redox sensitive, 2,3-dihydroxybenzoic acid (DH) functionalized chitosan/stearic acid microgels (DH-ChSt MGs) for controlled delivery of insecticide and capturing of heavy metal ions. DH-ChSt MGs (≈146 nm) are prepared by disulfide crosslinking of SH functionalized chitosan and stearic acid rendering them biodegradable. DH-ChSt MGs exhibit high loading (≈8 %) and encapsulation (≈85 %) efficiency for imidacloprid insecticide, and offer its prolonged release (≈75 % after 133 h) under reducing conditions. Functionalization with DH provides enhanced foliar adhesion on pea leaves. DH-ChSt MGs also bind Fe3+ very efficiently due to the strong chelation of Fe3+ by DH, offering the opportunity of supplying Fe3+ nutrient for plant care. MTT assay results using different cells confirm that DH-ChSt MGs are nontoxic up to the experimental concentration of 120 µg/mL. Additionally, reduced DH-ChSt MGs having free thiol groups are also capable of binding heavy metal ions, thus presenting the reported formulation as a promising platform for agriculture application.

Profiling the disintegration of BRPs released by massive wasp stings using serratiopeptidase: An in-silico insight.

Serratiopeptidase is a multifaceted therapeutic enzyme renowned for its anti-inflammatory, analgesic, anti-biofilm, fibrinolytic, and anti-edemic properties. It is vital to uncover more about the assets of such efficacious enzyme in order to facilitate their contribution in all health-related issues, notably inflammatory ailments. The current study sought to determine whether serratiopeptidase would disintegrate bradykinin related peptides (BRPs) from wasp venom in the same manner as it does with human bradykinin. To accomplish this objective, we docked selected BRPs onto the binding pocket of wild and previously identified mutant (N412D) of serratiopeptidase. Based on their docked scores, the top two BRPs were selected, and their conformational behavior was analyzed employing molecular dynamics studies. Additionally, thermodynamics end-state energy analysis reported that both the complexes exhibited higher stability and identical ΔG values when compared to the reference complex. Further, we condemned the external pulling forces on both peptides to observe the force needed in the disassociation process to endorse the binding affinity findings in terms of unbinding mechanism. This analysis suggested that BRP-7 (Wasp kinin PMM1) peptide was tightly anchored and laid out the highest pulling force to get detach from the active pocket of serratiopeptidase in contrast to the BRP-6 peptide. The current study endorses up the present findings and paves the way for serratiopeptidase to be used as an anti-angioedemic peptidase as well as a fixed-dose combination (FDC) in hypotensive drugs.

Dextran/eudragit S-100 based redox sensitive nanoparticles for colorectal cancer therapy.

Herein, we present disulfide crosslinked dextran/eudragit S-100 nanoparticles (DEEU NPs) (≈55 nm) for colorectal cancer treatment. These redox environment sensitive DEEU NPs are synthesized by simple oxidation of thiolated polymers in air. This approach allows avoiding the use of any additional chemical crosslinker. These DEEU NPs have high encapsulation efficiency for the doxorubicin (DOX) model drug (≈95%). The prepared DEEU NPs are redox sensitive owing to disulfide units and exhibit ≈80% DOX release in the reducing environment of GSH. Additionally, DOX-DEEU NPs display enhanced cytotoxicity for HCT116 cancer cells as compared to free DOX. Annexin V staining results also support the higher anticancer efficiency of DOX-DEEU NPs via induction of apoptosis. In vivo biodistribution results demonstrate that DEEU NPs can remain in the colon region for up to 24 hours. These results indicate that DEEU NPs can act as a promising platform for colorectal cancer treatment.

Biodegradable dual stimuli responsive alginate based microgels for controlled agrochemicals release and soil remediation.

To meet the growing food demand of increasing world population while reducing the harmful environmental effects of agrochemicals, development of smart nanoformulation is of prime importance. Herein, dual stimuli responsive alginate based microgels (OAlgDP MGs) (≈160 nm) are developed for controlled release of agrochemicals and soil remediation. These microgels are prepared using octyl amine functionalized alginate which is crosslinked by 3, 3'-dithiopropionohydrazide crosslinker providing both hydrazone and disulfide bonds in microgels network. OAlgDP MGs are further loaded with hydrophobic diuron herbicide displaying ≈85 % encapsulation efficiency. Sustained release of diuron is obtained in 2 mM GSH (≈100 % after 380 h) and at pH 5 (≈72 % after 240 h). Furthermore, OAlgDP MGs are nontoxic up to 150 µg/mL against HEK293T cells while their reduced form is capable of capturing the heavy metal ions (Cu2+ and Hg2+) showing the potential of the developed system for moving toward sustainable agriculture.

Identification of potential mutational hotspots in serratiopeptidase to address its poor pH tolerance issue.

Serratiopeptidase is the multifunctionality metalloendopeptidase extensively employed in biopharmaceutical and industrial biotechnology. Despite its poor pH tolerance, serratiopeptidase must withstand the highly acidic environment of the gastrointestinal tract to be used as a potent anti-inflammatory and analgesic medication. In earlier studies, post-translational deamination related mutations showed alteration in the net charge of protein's surface. Therefore, the current study aimed to enhance the acid resistance of serratiopeptidase via implementing computational interventions to screen out the most stable mutational hotspot. The methodology used in this study is as follows: (a) Higher accessibility to surface (b) 4 Å away from active site region to avoid interference with its proteolytic activity, and (c) By converting non-conserved amide residues to acidic residues. A docking study has been conducted to establish the substrate specificity and binding affinity to native and mutant proteins. The docking outcomes were then validated using molecular dynamic simulations to clarify each mutant's molecular stability and conformation while preserving their activity. The results showed that N412D is the best-screened mutant with negative electrostatic potential that can alter the overall charge on the protein's surface with increased H+ ions. Alteration in overall charge leads to protein surface more acidic that causes a common ion effect in stomach pH and act as a buffer which could stabilize the serratiopeptidase amid extreme pH.Communicated by Ramaswamy H. Sarma.

Redox responsive poly(allylamine)/eudragit S-100 nanoparticles for dual drug delivery in colorectal cancer.

Herein, we report redox responsive, colon cancer targeting poly(allylamine) (PA)/eudragit S-100 (EU) nanoparticles (PAEU NPs) (≈59 nm). These disulfide crosslinked PAEU NPs are developed via air oxidation of thiolated PA and thiolated EU, eliminating the need of any external crosslinking agent for dual drug delivery. PAEU NPs can effectively encapsulate both hydrophilic doxorubicin (DOX) and hydrophobic curcumin (Cur) drug with ≈85 % and ≈97 % encapsulation efficiency respectively. Here, the combination of drugs having different anticancer mechanism offers the possibility of developing nanosystem with enhanced anticancer efficacy. The developed PAEU NPs show good colloidal stability and low drug release under physiological conditions, while high DOX (≈98 %) and Cur (≈93 %) release is observed in reducing environment (10 mM GSH). Further, DOX and Cur loaded PAEU NPs exhibit higher cancer cell killing efficiency as compared to individual free drugs. In vivo biodistribution studies with Balb/C mice display the retention of PAEU NPs in the colon region up to 24 h presenting the developed approach as an efficient way for colorectal cancer therapy.

Environmentally benign approach for the efficient sequestration of methylene blue and coomassie brilliant blue using graphene oxide emended gelatin/κ-carrageenan hydrogels.

Herein, we report the synthesis and characterization of gelatin/κ-carrageenan crosslinked polyacrylic acid hydrogel (GT-CAG-cl-polyAA) and graphene oxide incorporated hydrogel nanocomposite (GOHNC) through a free radical crosslinking pathway. Under optimized reaction conditions, GT-CAG-cl-polyAA displayed 486 % maximum swelling percentage. TEM image depicted wrinkled silk veil wave-type surface morphology of graphene oxide (GO), whereas, the SEM analysis indicated the porous nature of the GT-CAG-cl-polyAA and GOHNC capable of accumulating a large number of water/dye molecules. GT-CAG-cl-polyAA exhibited 96.11 % and 82.16 % dye removal potential for the adsorption of methylene blue (MB) and coomassie brilliant blue (CB), respectively under optimized conditions. GOHNC enhanced the % dye removal efficiency (98.39 % for MB and 94.50 % for CB). The maximum adsorption capacity of GOHNC for the removal of CB and MB was 312.7 mg/g and 94.9 mg/g, respectively. The adsorption of CB and MB exhibited best fitting with Flory-Huggins adsorption isotherms data. The negative values of ΔG° and positive values of ΔS° which were obtained from the adsorption isotherm plot suggested the thermodynamic feasibility of the adsorption. Also, the samples were reusable for up to five consecutive cycles without any degradation and hence suggested a considerable pathway for the separation of textile dyes.

π-Conjugated Materials Derived From Boron-Chalcogenophene Combination. A Brief Description of Synthetic Routes and Optoelectronic Applications.

Functional materials composed of Boron-chalcogenophene conjugates have emerged as promising ensemble featuring commendable optoelectronic properties. This review describes the categories, synthetic routes and optoelectronic applications of a range of boron-chalcogenophene conjugates. Conjugation and linking of different types of tri- and tetra-coordinated boron moieties with chalcogenophenes have remained an important strategy for constructing a range of functional materials. Synthetic protocols have been devised to efficiently prepare such chemically robust conjugates, often exhibiting a myriad of photophysical properties, redox capabilities and also solid-state behaviors. Tin-boron and silicon-boron exchange protocols have been efficiently adapted to access these boron-chalcogenophenes. Few other commonly used methods namely, hydroboration of alkynes as well as electrophilic borylations are also mentioned. The chemical and electronic properties of such boron-chalcogenophene conjugates are directly influenced by the strong Lewis acid character of trivalent boranes which can further alter the intra- and inter- molecular Lewis acid-base interactions. Apart from the synthetic protocols, recent advances in the application of these boron-chalcogenophene conjugates towards analyte sensing, organic electronics, molecular switches and several other aspects will be discussed in this review.