Suppressing of milk-borne pathogenic using new water-soluble chitosan-azidopropanoic acid conjugate: Targeting milk-preservation quality improvement

Galloyl-oligochitosan nano-vehicles for effective and controlled propolis delivery targeting upgrading its antioxidant and antiproliferative potential

A new conjugate, galloyl-oligochitosan nanoparticles (GOCNPs), was fabricated and used as nano-vehicle for effective and controlled delivery of propolis extract (PE) in the form of PE#GOCNPs, targeting improving its pharmaceutical potential. H-bonding interactions between the carboxyl, amino, and hydroxyl groups of the GOCNPs and PE resulted in successful encapsulation, with an entrapment efficacy of 97.3 %. The PE#GOCNPs formulation also exhibited excellent physicochemical stability and time-triggered drug release characteristics under physiological conditions. Furthermore, PE#GOCNPs showed significant activity against MCF-7 and HEPG2 carcinoma cells by scavenging free oxygen radicals and upregulating antioxidant enzymes. Additionally, PE#GOCNPs displayed anti-inflammatory properties by increasing IL10 and reducing pro-inflammatory cytokines more effectively than celecoxib. Furthermore, PE#GOCNPs reduced the expression of epidermal growth factor receptor (EGFR) and survivin genes. Furthermore, the encapsulated PE demonstrated significant activity in suppressing sonic hedgehog protein (SHH). The use of GOCNPs in combination with propolis presents a promising new strategy for chemotherapy with reduced toxicity and enhanced biocompatibility. This novel approach has the potential to revolutionize the field of chemotherapy. Future studies should focus on the application of the encapsulated PE in various cancer cell lines, distinct gene expression factors, and cell cycles.

Carboxymethyl-imidazolium O-vanillin Schiff base grafted into NH2-tagged MIL-101 (Cr) for effective removal of cupric ions from aqueous effluents

A novel adsorbent (MIL-CMIVSB) was fabricated by modification of H2N-MIL-101(Cr) with carboxymethyl-imidazolium O-vanillin Schiff base. The MIL-CMIVSB's physicochemical characteristics were examined using the pertinent characterization methods. NH2-MIL-101(Cr) has a BET surface area of 1492.4 m2g-1, while MIL-CMIVSB adsorbent had 1278.7 m2g-1. Batch adsorption experiments examined the MIL-CMIVSB's cupric ion adsorption capacity from aqueous solutions at different adsorbent doses (0.1-3 mg), pH (2.0-10.0), contact times (0-240 min), metal ion initial concentrations (10-300 mg/L), and temperatures (298-308 K). The optimum conditions were 1 mg/mL of MIL-CMIVSB adsorbent, 46 min adsorption time, pH 7, 100 ppm initial cupric ion concentration, and 303 K temperature. MIL-CMIVSB effectively and selectively removes cupric ions with an adsorption capability of 359.05 ± 12.06 mg/g. The nonlinear Liu isotherm governed Cu(II) sorption performance on MIL-CMIVSB (KL = 0.257 ± 0.01 mg/g, R2 = 0.99892) and pseudo-2nd-order kinetically (k2 = 0.00116 × 10-4 g/mg min, R2 = 0.99721).

Natural Antimicrobials in Dairy Products: Benefits, Challenges, and Future Trends

This review delves into using natural antimicrobials in the dairy industry and examines various sources of these compounds, including microbial, plant, and animal sources. It discusses the mechanisms by which they inhibit microbial growth, for example, by binding to the cell wall's precursor molecule of the target microorganism, consequently inhibiting its biosynthesis, and interfering in the molecule transport mechanism, leading to cell death. In general, they prove to be effective against the main pathogens and spoilage found in food, such as Escherichia coli, Staphylococcus aureus, Bacillus spp., Salmonella spp., mold, and yeast. Moreover, this review explores encapsulation technology as a promising approach for increasing the viability of natural antimicrobials against unfavorable conditions such as pH, temperature, and oxygen exposure. Finally, this review examines the benefits and challenges of using natural antimicrobials in dairy products. While natural antimicrobials offer several advantages, including improved safety, quality, and sensory properties of dairy products, it is crucial to be aware of the challenges associated with their use, such as potential allergenicity, regulatory requirements, and consumer perception. This review concludes by emphasizing the need for further research to identify and develop effective and safe natural antimicrobials for the dairy industry to ensure the quality and safety of dairy products for consumers.

Biomimetic zwitterionic copolymerized chitosan as an articular lubricant

Restoration of the lubrication functions of articular cartilage is an effective treatment to alleviate the progression of osteoarthritis (OA). Herein, we fabricated chitosan-block-poly(sulfobetaine methacrylate) (CS-b-pSBMA) copolymer via a free radical polymerization of sulfobetaine methacrylate onto activated chitosan segment, structurally mimicking the lubricating biomolecules on cartilage. The successful copolymerization of CS-b-pSBMA was verified by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and 1H nuclear magnetic resonance. Friction test confirmed that the CS-b-pSBMA copolymer could achieve an excellent lubrication effect on artificial joint materials such as Ti6Al4V alloy with a coefficient of friction as low as 0.008, and on OA-simulated cartilage, better than the conventional lubricant hyaluronic acid, and the adsorption effect of lubricant on cartilage surface was proved by a fluorescence labeling experiment. In addition, CS-b-pSBMA lubricant possessed an outstanding stability, which can withstand enzymatic degradation and even a long-term storage up to 4 weeks. In vitro studies showed that CS-b-pSBMA lubricant had a favorable antibacterial activity and good biocompatibility. In vivo studies confirmed that the CS-b-pSBMA lubricant was stable and could alleviate the degradation process of cartilage in OA mice. This biomimetic lubricant is a promising articular joint lubricant for the treatment of OA and cartilage restoration.

Synthesis, properties, and applications of a polyampholyte hydroxypropyl chitosan derivative with the phenylboronic acid functional group

Phenylboronic acid (PBA) groups are effective in building glucose-responsive drug delivery systems. Chitosan (CS) offers distinct advantages in the construction of PBA-based biomaterials, such as biodegradability and biocompatibility. However, challenges still persist due to the limited solubility of CS. This study proposes an efficient approach to introduce PBA groups into CS chains within 1 h via the O-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU)-mediated amidation between 3-carboxyphenylboronic acid (CPBA) and O-hydroxypropyl chitosan (HPCS). The results showed that a wide range of substitution degrees, from 0.15 to 0.78, could be finely controlled by the amount of CPBA added. Furthermore, the obtained novel carboxyphenylboronic acid-grafted hydroxypropyl chitosan (PBA-HPCS) derivative showed enhanced crystallinity and thermostability compared to HPCS, and it demonstrated solubility in an alkaline solution. Based on the reversible bonding between the boronic acid group and cis-1,2/1,3-diols, PBA-HPCS was successfully used as an efficient crosslinker for the preparation of hydrogels incorporating sorbitol and polyhydroxy polymers, such as guar gum and polyvinyl alcohol. These hydrogels exhibited rapid gelation, rapid self-healing, injectability, and responsiveness to glucose and pH. These findings suggest that PBA-HPCS holds promise for advancing the development of PBA-based biomaterials.

Exploring the chondroitin sulfate nanogel's potential in combating nephrotoxicity induced by cisplatin and doxorubicin-An in-vivo study on rats

In this study, we aim to unveil the potential of itaconyl chondroitin sulfate nanogel (ICSNG) in tackling chronic kidney diseases triggered by the administration of CDDP and doxorubicin (Adriamycin, ADR). To that end, the new drug delivery system (ICSNG) was initially prepared, characterized, and loaded with the target drugs. Thereafter, the in-vivo studies were performed using five equally divided groups of 100 male Sprague-Dawley (SD) rats. Biochemical evaluation and immunohistochemistry studies have revealed the renal toxicity and the ameliorative effects of ICSNG on renal function. When ICSNG-based treatments were contrasted with the CDDP and ADR infected groups, they significantly increased paraoxonase-1 (PON-1), superoxide dismutase (SOD), catalase (CAT) and albumin activity and significantly decreased nitric oxide (NO), tumor necrosis factor alpha (TNF-α), creatinine, urea, and cyclooxygenase-2 (COX-2) activity (p < 0.001). The findings of the current study imply that ICSNG may be able to lessen renal inflammation and damage in chronic kidney disorders brought on by the administration of CDDP and ADR. Interestingly, according to the estimated selectivity indices, the ICSNG-encapsulated drugs have demonstrated superior selectivity for cancer MCF-7 cells, over healthy HSF cells, in comparison to the bare drugs.

Harnessing the Potential of Chitosan and Its Derivatives for Enhanced Functionalities in Food Applications

As one of the most abundant natural polysaccharides that possess good biological activity, chitosan is extracted from chitin. Its application in the food field is being increasingly valued. However, chitosan extraction is difficult, and its poor solubility limits its application. At present, the extraction methods include the acid-base method, new chemical methods, and biological methods. The extraction rates of chitin/chitosan are 4-55%, 13-14%, and 15-28%, respectively. Different chemical modifications have different effects on chitosan, making it applicable in different fields. This article reviews and compares the extraction and chemical modification methods of chitosan, emphasizing the importance of green extraction methods. Finally, the application prospects of chitosan in the food industry are discussed. This will promote the understanding of the advantages and disadvantages of different extraction methods for chitosan as well as the relationship between modification and application, providing valuable insights for the future development of chitosan.

Biosynthesized silver nanoparticles-capped chondroitin sulfate nanogel targeting microbial infections and biofilms for biomedical applications

Medical devices are essential for patient care, but they can also serve as havens for dangerous microbes and the development of biofilm, which can lead to serious infections and higher death rates. To meet these issues, it is crucial to develop novel and effective antimicrobial coatings for medical devices. In this context, we have developed a new biofunctionalized nanosilver (ICS-Ag), employing itaconyl-chondroitin sulfate nanogel (ICSNG) as a synergistic reducing and stabilizing agent, to effectively eradicate microbial infections and biofilm formation. The antibacterial investigations showed that ICS-Ag nanocomposite is an intriguing antibiotic with excellent antibacterial indices (MIC/MBC (μg/mL): 2.29/4.58, 1.25/2.50, and 1.36/1.36 against S. aureus, E. coli, and P. aeruginosa, respectively), as well as antifungal capacity. Furthermore, ICS-Ag demonstrated efficacy superior to that of the antibiotic (ciprofloxacin, Cipro) against both Gram-positive and Gram-negative bacterial biofilms. TEM images of untreated and treated bacterial strains demonstrate synergistic actions that harm the bacterial cytomembrane, leading to the release of intracellular contents and bacterial death. Interestingly, ICS-Ag shows excellent biocompatibility, with an IC50 value (71.25 μg/mL) higher than MICs against tested microbes. Overall, the ICS-Ag film may provide multifunctional antimicrobial coatings for medical equipment to reduce microbial contamination and biofilm development.

Comparison of the ameliorative roles of crab chitosan nanoparticles and mesenchymal stem cells against cisplatin-triggered nephrotoxicity

AIM

In the present investigation, we compared the effects of mesenchymal stem cells extracted from bone marrow (BMSCs) and crab chitosan nanoparticles (CCNPs) on renal fibrosis in cisplatin (CDDP)-induced kidney injury rats.

MATERIAL AND METHODS

90 male Sprague-Dawley (SD) rats were divided into two equal groups and alienated. Group I was set into three subgroups: the control subgroup, the CDDP-infected subgroup (acute kidney injury), and the CCNPs-treated subgroup. Group II was also divided into three subgroups: the control subgroup, the CDDP-infected subgroup (chronic kidney disease), and the BMSCs-treated subgroup. Through biochemical analysis and immunohistochemical research, the protective effects of CCNPs and BMSCs on renal function have been identified.

RESULTS

CCNPs and BMSC treatment resulted in a substantial rise in GSH and albumin and a decrease in KIM-1, MDA, creatinine, urea, and caspase-3 when compared to the infected groups (p < 0.05).

CONCLUSION

According to the current research, chitosan nanoparticles and BMSCs may be able to reduce renal fibrosis in acute and chronic kidney diseases caused by CDDP administration, with more improvement of kidney damage resembling normal cells after CCNPs administration.

Therapeutic potential and protection enhancement of mesenchymal stem cell against cisplatin-induced nephrotoxicity using hyaluronic acid-chitosan nanoparticles as an adjuvant

A newly synthesized nanoplatform of hyaluronic acid and chitosan nanoparticles (HA/CNPs) was applied to improve the therapeutic efficacy and protection of bone marrow mesenchymal stem cells (BM-MSCs) against cisplatin (CDDP)-induced nephrotoxicity in rats. CDDP administration causes significant increases in levels of serum creatinine (SCr), urea, and KIM-1 coupled with significant albumin level falls, as indicative of acute renal dysfunction. Moreover, the level of the antioxidant enzyme (GSH) was significantly decreased, while the levels of lipid peroxidation (MDA) and inflammatory (IL-6) and apoptotic (caspase-3) markers were significantly increased, indicating a decline in the kidney's antioxidant defense and increased inflammation. In contrast, when rats were pre-treated with either MSCs or MSCs-HA/CNPs before receiving CDDP, the levels of SCr, urea, KIM-1, MDA, IL-6, and caspase-3 were significantly decreased with simultaneous significant rises in GSH and albumin, impelling a great improvement in the antioxidant and anti-inflammatory defenses of the kidney as well as its functions. Intriguingly, MSCs-HA/CNPs were more effective against caspase-3 than MSCs alone, revealing the high anti-apoptotic capability of HA/CNPs. This finding suggests that HA/CNPs could effectively protect MSCs from oxidative stress and apoptosis and thus increase their stability and longevity.

Development of ternary nanoformulation comprising bee pollen-thymol oil extracts and chitosan nanoparticles for anti-inflammatory and anticancer applications

Due to the beneficial nutritional and medicinal characteristics of bee honey and thymol oil as antioxidants, anti-inflammatory agents, and antibacterial agents, they have been used since ancient times. The current study aimed to construct a ternary nanoformulation (BPE-TOE-CSNPs NF) through the immobilization of the ethanolic extract of bee pollen (BPE) with thymol oil extract (TOE) into the matrix of chitosan nanoparticles (CSNPs). The antiproliferative activity of new NF (BPE-TOE-CSNPs) against HepG2 and MCF-7 cells was investigated. The BPE-TOE-CSNPs showed significant inhibitory activity for the production of the inflammatory cytokines in HepG2 and MCF-7, with p < 0.001 for both TNF-α and IL6. Moreover, the encapsulation of the BPE and TOE in CSNPs increased the efficacy of the treatment and the induction of valuable arrests for the S phase of the cell cycle. In addition, the new NF has a great capacity to trigger apoptotic mechanisms through caspase-3 expression upregulation in cancer cells by two-fold among HepG2 cell lines and nine-fold among MCF-7 which appeared to be more susceptible to the nanoformulation. Moreover, the nanoformulated compound has upregulated the expression of caspase-9 and P53 apoptotic mechanisms. This NF may shed light on its pharmacological actions by blocking specific proliferative proteins, inducing apoptosis, and interfering with the DNA replication process.

Chitin and Chitosan as Polymers of the Future-Obtaining, Modification, Life Cycle Assessment and Main Directions of Application

Natural polymers are very widespread in the world, which is why it is so important to know about the possibilities of their use. Chitin is the second most abundant reproducible natural polymer in nature; however, it is insoluble in water and basic solvents. Chitin is an unused waste of the food industry, for which there are possibilities of secondary management. The research led to obtaining a soluble, environmentally friendly form of chitin, which has found potential applications in the many fields, e.g., medicine, cosmetics, food and textile industries, agriculture, etc. The deacetylated form of chitin, which is chitosan, has a number of beneficial properties and wide possibilities of modification. Modification possibilities mean that we can obtain chitosan with the desired functional properties, facilitating, for example, the processing of this polymer and expanding the possibilities of its application, also as biomimetic materials. The review contains a rich description of the possibilities of modifying chitin and chitosan and the main directions of their application, and life cycle assessment (LCA)-from the source of the polymer through production materials to various applications with the reduction of waste.

Antibacterial and antibiofilm activity of mannose-modified chitosan/PMLA nanoparticles against multidrug-resistant Helicobacter pylori

Because of the apparent stasis in antibiotic discoveries and the growth of multidrug resistance, Helicobacter pylori-associated gastric infections are difficult to eradicate. In the search for alternative therapy, the reductive amination of chitosan with mannose, followed by ionic gelation, produced mannose functionalized chitosan nanoparticles. Then, molecular docking and molecular dynamics (MD) simulations were conducted with H. pylori lectin (HPLectin) as a target protein involved in bacterium adherence to host cells, biofilm formation, and cytotoxicity. Changes in zeta potential and FTIR spectroscopy revealed that chitosan was functionalized with mannose. Time-kill, polystyrene adherence, and antibiofilm studies were utilized to assess nanoparticles as an alternative antibacterial treatment against a resistant gastric pathogen. Man-CS-Nps were discovered to have effective anti-adherence and biofilm disruption characteristics in suppressing the development of resistant H. pylori. In addition, bioimaging studies with CLSM, TEM, and SEM illustrated that Man-CS-Nps interacted with bacterial cells and induced membrane disruption by creating holes in the outer membranes of the bacterial cells, resulting in the leakage of amino acids. Importantly, molecular docking and 20 ns MD simulations revealed that Man-CS-Nps inhibited the target protein through slow-binding inhibition and hydrogen bond interactions with active site residues. As a consequence of the findings of this study, the Man-CS-Nps is an excellent candidate for developing alternative therapies for the increasing incidences of resistant gastric infections.

Cellulosic fabrics modified with polyphosphonium chitosan hydrazone-TiO2-Ag nanobiocomposites for multifunctional applications

Bionanocomposites (BNC1,2) of binary (PPCH-Ag) and ternary (PPCH-TiO₂-Ag) (PPCH = polyphosphonium chitosan-hydrazone) have been synthesized and immobilized on cellulosic fabrics (CFs) using an environmentally friendly single-step in situ methodology. The results of FTIR, TGA, EDX, SEM, and TEM investigations showed that PPCH and its BNCs were successfully formed on the surface layer of fabrics. Moreover, the BNC2-coated cloth exhibited a superhydrophobic behavior as revealed from the values of water contact angle (WCA) 152.1° and slide angle (SA) 8.7°. The cytotoxicity experiments on epithelial cells confirmed the safety of treated fabrics for human cells. The antimicrobial capabilities of the BNCs-treated textiles were greatly enhanced, with a small preference for BNC1-coated fabric, as compared to the native or other treated fabrics. In contrast, the BNC2-coated fabric demonstrated the highest anti-UV protection capabilities as indicated by its great capacity to reduce the UV transmission (UV-A, 2.1 %; UV-B, 1.8 %) as well as its UPF value (49.2). The durability tests revealed the high resistance of BNC2-CF against harsh washing conditions and their acquired functions sustainability up to 20 washing cycles.

Upgrading the Transdermal Biomedical Capabilities of Thyme Essential Oil Nanoemulsions Using Amphiphilic Oligochitosan Vehicles

(1) Background: Thymus vulgaris L. (thyme) essential oil (TEO) has gained much attention because of its long history of medicinal usage. However, the lack of precise chemical profiling of the TEO and methods to optimize the bioactivity and delivery of its constituents has hampered its research on quality control and biological function; (2) Methods: The current study aimed to analyze the TEO’s chemical composition using the GC-MS method and identify its key components. Another objective of this work is to study the impact of the protective layer of amphiphilic oligochitosan (AOC) on the physicochemical stability and transdermal potentials of TEO multilayer nanoemulsions formulated by the incorporation of TEO, Tween80, lecithin (Lec), and AOC; (3) Results: The AOC protective layer significantly improved the stability of TEO-based NEs as revealed by the constancy of their physicochemical properties (particle size and zeta potential) during storage for a week. Excessive fine-tuning of thyme extract NEs and the AOC protective layer’s persistent positive charge have been contributed to the thyme extract’s improved anti-inflammatory, transdermal, and anti-melanoma potentials; (4) Conclusions: the AOC-coated NEs could offer novel multifunctional nanoplatforms for effective transdermal delivery of lipophilic bioactive materials.

Quaternized Chitosan Thiol Hydrogel-Thickened Nanoemulsion: A Multifunctional Platform for Upgrading the Topical Applications of Virgin Olive Oil

(1) Background: Virgin olive oil (VOO) has attracted the attention of many researchers due to its nutritional and medicinal values. However, VOO’s biological applications have been limited due to a lack of precise chemical profiling and approach to increase the physicochemical characteristics, bioactivity, and delivery of its bioactive components; (2) Methods: The current study intended to evaluate the chemical composition of VOO using the GC-MS technique and determine its major components. Furthermore, the effect of incorporating VOO into Tween 80-lecithin nanoemulsion (OONE) and a quaternized trimethyl chitosan-thiol (TMCT) hydrogel-thickened nanoemulsion system (OOHTN) on its physicochemical characteristics and biological potentials will be investigated; (3) Results: The VOO-based NEs’ physicochemical properties (particle size and zeta potential) were steady during storage for four weeks owing to the inclusion of the protective TMCT hydrogel network to OONE. Excessive fine-tuning of olive oil nanoemulsion (OONE) and the TMCT protective network’s persistent positive charge have contributed to the oil’s improved antimicrobial, anti-biofilm, and antioxidant potentials; (4) Conclusions: The Tween 80-lecithin-TMCT nanosystem might provide a unique and multifunctional nanoplatform for efficient topical therapy as well as the transdermal delivery of lipophilic bioactive compounds.

Synthesis and characterization of chitosan nanoparticles loaded with greater celandine (Chelidonium majus L.) essential oil as an anticancer agent on MCF-7 cell line

Essential oils (EOs) of greater celandine (GC) roots and leaves were extracted, and gas chromatography-mass spectrometry (GC-MS) was used for analyzing them. Then they were loaded into chitosan nanoparticles (CNPs) using emulsion-ionic gelation method. CNPs loaded with greater celandine root essential oil (GCREO) and leave essential oil (GCLEO) were synthesized (size 76.5-115.3 nm) using an emulsion-ionic gelation method. Fourier Transform Infrared (FT-IR), spectroscopy, scanning electron microscope (SEM), and dynamic light scattering (DLS) were used for characterization of the formed NPs. Good encapsulation efficiency was confirmed for GCREO (62.5%) and GCLEO (69.1%) in CNPs. According to the MTT results, the synthesized NPs showed a dose-dependent effect on MCF-7 cell line. The inhibitory concentration (IC₅₀) values for GCREO, GCLEO, CSNRs-GCREO and CNPs-GCLEO samples were 126.4, 90.2, 77.6, and 41.5 μg/mL, respectively. The highest rate of apoptosis was obtained in the CNPs-GCLEO group (63.73%). The results revealed that the cytotoxicity of CSNRs-GCREO and CNPs-GCLEO against MCF-7 cell line was significantly higher than that of their free form, implying that encapsulation of GCREO and GCLEO in CNPs is an efficient technique for improving their anti-cancer activity against MCF-7 cell line.

Bactericidal and antibiofilm properties of Rumex japonicus Houtt. on multidrug-resistant Staphylococcus aureus isolated from milk

Multidrug-resistant (MDR) Staphylococcus aureus and its biofilm formation have been challenging to control in milk and dairy industries. Biofilms formed by Staph. aureus may result in the failure of antibacterial agents and disinfectants to penetrate the biofilm in an attempt to control contamination. Novel natural antibacterial agents are required to combat MDR bacteria and biofilms. In this study, we evaluated the bactericidal, antibiofilm, and antimotility effects of Rumex japonicus Houtt. (RJH) extract on MDR Staph. aureus isolated from milk. The RJH extract exhibited good antibacterial activity against MDR strains with minimum inhibitory concentrations (MIC) ranging from 0.78 to 6.25 mg/mL and minimum bactericidal concentrations ranging from 3.125 to 12.5 mg/mL. The extract showed strong inhibition of biofilm formation (81.9%) at sub-MIC value and eradication of biofilm at higher concentrations. The motility of Staph. aureus was effectively blocked by the extract. Major compounds emodin, chrysophanol, and physcion were identified in RJH extract using HPLC-linear trap quadrupole (LTQ)/Orbitrap-mass spectrometry. The extract was nontoxic to human epithelial cell lines such as Caco-2 and HT-29 cell lines at concentrations ranging from 0.1 to 0.5 mg/mL, and from 0.1 to 0.75 mg/mL, respectively. These findings suggest that RJH extract could be an alternative to synthetic preservatives in milk and dairy products.

Antimicrobial Activity of Chemically and Biologically Treated Chitosan Prepared from Black Soldier Fly (Hermetia illucens) Pupal Shell Waste

Globally, the broad-spectrum antimicrobial activity of chitin and chitosan has been widely documented. However, very little research attention has focused on chitin and chitosan extracted from black soldier fly pupal exuviae, which are abundantly present as byproducts from insect-farming enterprises. This study presents the first comparative analysis of chemical and biological extraction of chitin and chitosan from BSF pupal exuviae. The antibacterial activity of chitosan was also evaluated. For chemical extraction, demineralization and deproteinization were carried out using 1 M hydrochloric acid at 100 °C for 2 h and 1 M NaOH for 4 h at 100 °C, respectively. Biological chitin extraction was carried out by protease-producing bacteria and lactic-acid-producing bacteria for protein and mineral removal, respectively. The extracted chitin was converted to chitosan via deacetylation using 40% NaOH for 8 h at 100 °C. Chitin characterization was done using FTIR spectroscopy, while the antimicrobial properties were determined using the disc diffusion method. Chemical and biological extraction gave a chitin yield of 10.18% and 11.85%, respectively. A maximum chitosan yield of 6.58% was achieved via chemical treatment. From the FTIR results, biological and chemical chitin showed characteristic chitin peaks at 1650 and 1550 cm⁻¹—wavenumbers corresponding to amide I stretching and amide II bending, respectively. There was significant growth inhibition for Escherichia coli, Bacillus subtilis,Pseudomonas aeruginosa,Staphylococcus aureus, and Candida albicans when subjected to 2.5 and 5% concentrations of chitosan. Our findings demonstrate that chitosan from BSF pupal exuviae could be a promising and novel therapeutic agent for drug development against resistant strains of bacteria.

Chemotherapeutic and chemopreventive potentials of ρ-coumaric acid - Squid chitosan nanogel loaded with Syzygium aromaticum essential oil

One of the most important trends in chemotherapy is the development of green chemotropic drugs with maximal activity and minimal side effects. The nanoencapsulation of phytochemical oils with natural polymers has been documented as a promising approach to producing nanodrugs with sustainable bioactivity and prolonged stability. In this context, Syzygium aromaticum essential oil (SAEO) and ultrasound-assisted deacetylated chitosan (UCS₃) were successfully extracted from clove buds and squid pens, respectively. Grafting of UCS₃ by ρ-coumaric acid (ρCA) has been performed to fabricate the ρCACS nanogel which was used for nanoencapsulation of SAEO to yield SAEO-loaded nanogel (ρCACS@SAEO). The findings of spectral, thermal, and morphological analyses have confirmed the success of the formation of new materials and SAEO encapsulation, as well. Based on the findings of the in vitro antimicrobial, antioxidant, and anticancer studies, the nanoencapsulation of SAEO by ρCACS has significantly boosted its chemotherapeutic effects, compared to unencapsulated oil. Therefore, ρCACS@SAEO nanogel could be considered as a multifunctional chemotherapeutic/chemopreventive agent for prevention or therapy of pathologies induced by oxidative stress, microbial infection, and breast and skin cancer.

Chitosan nanoparticles fabricated through host-guest interaction for enhancing the immunostimulatory effect of CpG oligodeoxynucleotide

CpG oligodeoxynucleotides (CpG ODNs) which can induce innate immune responses and promote adaptive immune responses, are powerful tools in defeating diseases. Here, a novel chitosan nanoparticle (CS-NPs) based on host-guest interaction has been designed for encapsulation and delivery of CpG ODNs for the first time. The CS-NPs exhibited high encapsulation efficiency (98.3%) of CpG ODNs and remained stable in storage under room temperature for at least 7 days. CS-NPs can also prevent CpG ODN diffusion at pH 7. The results of confocal laser scanning microscope images and flow cytometry show that CS-NPs can also be efficiently delivered into living cells. Furthermore, CpG@CS-NPs can increase the immunostimulatory activity of CpG ODNs. Raw 264.7 cells treated with CpG@CS-NPs demonstrated upregulation of both TNF-α and IL-6 cytokines by 13% and 40%, respectively. The newly developed CpG@CS-NPs were thus identified as an efficient system to deliver CpG-ODNs to treat various diseases.

Ionic chitosan Schiff bases supported Pd(II) and Ru(II) complexes; production, characterization, and catalytic performance in Suzuki cross-coupling reactions

Taking the advantage of multifunctional characteristics of chitosan (CS), we have developed new scaffolds (imidazolium-vanillyl-chitosan Schiff bases (IVCSSBs)) for supporting Pd(II) and Ru(II) ions in catalyzing Suzuki coupling reactions. The structures of new materials were described based on their elemental, spectral, thermal, and microscopic analysis. The strong interactions between the binding sites of IVCSSB ligand (OH, H-C=N, and OCH₃ groups) and Pd(II) ions resulted in the formation of an excellent heterogeneous catalyst (Pd(II)IVCSSB1) with amazing catalytic activity (up to 99%) and highly stable in the reaction medium. The reusability experiments for Pd(II)IVCSSB₁ revealed that there is no appreciable decrease in its catalytic activity even after five consecutive operation runs. Furthermore, this heterogeneous catalyst showed an excellent selectivity toward the cross-coupling reaction where no homo-coupling byproducts were observed in the ¹H NMR spectra of the obtained products. Consequently, the present ionic catalytic system may open a new window for a novel generation of ionic bio-based catalysts for organic transformations.

Dual ionic liquid-based crosslinked chitosan for fine-tuning of antifouling, water throughput, and denitrification performance of polysulfone membrane

This study aimed to design a facile and efficient protocol for upgrading the performance indices of polysulfone (PS) membrane (porosity, hydrophilicity, pure water flux (PWF), surface charge, and fouling-resistance) by blending with newly synthesized poly(ionic) crosslinked chitosan Schiff bases (PICCSBs). The PS-PICCSBs mixed-matrix membranes (MMMs) have successfully fabricated and characterized based on spectral and microscopic analyses, porosity, zeta potential, water contact angle, and water uptake (wettability) measurements. The PWF, fouling-resistance against bovine serum albumin (BSA), as well as ion exchange capacity (IEC) against nitrate anion were studied. The wettability, hydrophilicity and overall porosity of new MMMs have greatly increased, in comparison to a pristine PS membrane (M₀). In addition, blending of PS with PICCSBs resulted in switching its surface from negatively- to positively-charged. The PWF of MMMs has increased to reach a maximum value of 238.6 L/m² h for MMM₁ (9.3-fold higher than M₀). Meanwhile, BSA rejection has declined from 96.62% for M₀ to 41.9% for MMM₁. The fouling parameters results of MMMs indicated their low fouling propensity. The IEC of nitrate anions revealed that the nitrate uptake by MMM₁ is higher than that for M₀ and MMM₂ by 34% and 14%, respectively.

Regeneration behavior of chitosan from ionic liquid using water and alcohols as anti-solvents

While ionic liquids (ILs) have been considered as effective and "green" solvents for biopolymer processing, regeneration of IL-dissolved biopolymers could largely impact biopolymer structure and properties. This study indicates that the reconstitution of chitosan structure during regeneration from 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) depends on anti-solvent (water, methanol or ethanol) largely. Irrespective of anti-solvent, the chitosan chemical structure was not varied by dissolution or regeneration. With water, the regenerated chitosan had the highest crystallinity index of 54.18%, followed by those with methanol (35.07%) and ethanol (25.65%). Water as an anti-solvent could promote chitosan chain rearrangement, leading to the formation of an ordered aggregated structure and crystallites. Density functional theory (DFT) simulation indicates that the number of hydrogen bonds formed between anti-solvents and [Emim][OAc] was in the order of water > methanol > ethanol. With water used for regeneration, the aggregation and rearrangement of chitosan chains occurred more easily.