Versatile carboxymethyl chitin and chitosan nanomaterials: a review

Preparation and evaluation of microencapsulated delivery system of recombinant interferon alpha protein from rainbow trout

Diseases caused by viruses pose a significant risk to the health of aquatic animals, for which there are presently no efficacious remedies. Interferon (IFN) serving as an antiviral agent, is frequently employed in clinical settings. Due to the unique living conditions of aquatic animals, traditional injection of interferon is cumbersome, time-consuming and labor-intensive. This study aimed to prepare IFN microcapsules through emulsion technique by using resistant starch (RS) and carboxymethyl chitosan (CMCS). Optimization was achieved using the Box-Behnken design (BBD) response surface technique, followed by the creation of microcapsules through emulsification. With RS at a concentration of 1.27 %, a water‑oxygen ratio of 3.3:7.4, CaCl2 at 13.67 %, CMCS at 1.04 %, the rate of encapsulation can escalate to 80.92 %. Rainbow trout infected with Infectious hematopoietic necrosis virus (IHNV) and common carp infected with Spring vireemia (SVCV) exhibited a relative survival rate (RPS) of 65 % and 60 % after treated with IFN microcapsules, respectively. Moreover, the microcapsules effectively reduced the serum AST levels and enhanced the expression of IFNα, IRF3, ISG15, MX1, PKR and Viperin in IHNV-infected rainbow trout and SVCV-infected carp. In conclusion, this integrated IFN microcapsule showed potential as an antiviral agent for treatment of viral diseases in aquaculture.

Hydrogel Loaded with Peptide-Containing Nanocomplexes: Symphonic Cooperation of Photothermal Antimicrobial Nanoparticles and Prohealing Peptides for the Treatment of Infected Wounds

Current treatment for chronic infectious wounds is limited due to severe drug resistance in certain bacteria. Therefore, the development of new composite hydrogels with nonantibiotic antibacterial and pro-wound repair is important. Here, we present a photothermal antibacterial composite hydrogel fabricated with a coating of Fe2+ cross-linked carboxymethyl chitosan (FeCMCS) following the incorporation of melanin nanoparticles (MNPs) and the CyRL-QN15 peptide. Various physical and photothermal properties of the hydrogel were characterized. Cell proliferation, migration, cycle, and free-radical scavenging activity were assessed, and the antimicrobial properties of the hydrogel were probed by photothermal therapy. The effects of the hydrogel were validated in a model of methicillin-resistant Staphylococcus aureus (MRSA) infection with full-thickness injury. This effect was further confirmed by changes in cytokines associated with inflammation, re-epithelialization, and angiogenesis on the seventh day after wound formation. The MNPs demonstrated robust photothermal conversion capabilities. The composite hydrogel (MNPs/CyRL-QN15/FeCMCS) promoted keratinocyte and fibroblast proliferation and migration while exhibiting high antibacterial efficacy, effectively killing more than 95% of Gram-positive and Gram-negative bacteria. In vivo study using an MRSA-infected full-thickness injury model demonstrated good therapeutic efficacy of the hydrogel in promoting regeneration and remodeling of chronically infected wounds by alleviating inflammatory response and accelerating re-epithelialization and collagen deposition. The MNPs/CyRL-QN15/FeCMCS hydrogel showed excellent antibacterial and prohealing effects on infected wounds, indicating potential as a promising candidate for wound healing promotion.

Exploring modified chitosan-based gene delivery technologies for therapeutic advancements

One of the critical steps in gene therapy is the successful delivery of the genes. Immunogenicity and toxicity are major issues for viral gene delivery systems. Thus, non-viral vectors are explored. A cationic polysaccharide like chitosan could be used as a nonviral gene delivery vector owing to its significant interaction with negatively charged nucleic acid and biomembrane, providing effective cellular uptake. However, the native chitosan has issues of targetability, unpacking ability, and solubility along with poor buffer capability, hence requiring modifications for effective use in gene delivery. Modified chitosan has shown that the "proton sponge effect" involved in buffering the endosomal pH results in osmotic swelling owing to the accumulation of a greater amount of proton and chloride along with water. The major challenges include limited exploration of chitosan as a gene carrier, the availability of high-purity chitosan for toxicity reduction, and its immunogenicity. The genetic drugs are in their infancy phase and require further exploration for effective delivery of nucleic acid molecules as FDA-approved marketed formulations soon.

Exploring the potential of quercetin/aspirin-loaded chitosan nanoparticles coated with Eudragit L100 in the treatment of induced-colorectal cancer in rats

Growing evidence suggests quercetin and aspirin may have anticancer properties, notably in the case of colorectal cancer. The goal of this study was to create Pluronic F127 and polyethylene glycol4000 solid dispersion-loaded chitosan nanoparticles for colonic quercetin and aspirin delivery. In 1:1 polymeric stoichiometric ratio, solubility and complex formation were verified. Solid dispersion-loaded chitosan nanoparticles with a diameter of 244.45 ± 8.5 nm, a surface charge of 34.1 ± 3.3 mV, and encapsulation effectiveness of 76.3 ± 4.3% were generated under ideal conditions. In some cases, coating with Eudragit L100 resulted in a decrease in zeta potential and an increase in particle size. The coated formulation released the actives in a pH-dependent manner, considering their physicochemical features. Surprisingly, when compared to the actives' suspension and uncoated formulation, the coated formulation had greater anti-inflammatory efficacy, with a substantial reduction of PGE2 and IL-8 production in colonic tissues (16.9 ± 7.9 ng/g tissue and 134.9 ± 10.1 pg/g tissue, respectively). It also reversed most of the dimethyl hydrazine-induced histological alterations in the colon. It also demonstrated a greater reduction in TNF expression in colonic tissues. As a result, Eudragit L100-coated QT/AS-loaded chitosan nanoparticles are suggested to provide a potential platform for colonic delivery of quercetin and aspirin.

Nanopeptide C-I20 as a novel feed additive effectively alleviates detrimental impacts of soybean meal on mandarin fish by improving the intestinal mucosal barrier

Antibacterial peptide has been widely developed in cultivation industry as feed additives. However, its functions in reducing the detrimental impacts of soybean meal (SM) remain unknown. In this study, we prepared nano antibacterial peptide CMCS-gcIFN-20H (C-I20) with excellent sustained-release and anti-enzymolysis, and fed mandarin fish (Siniperca chuatsi) with a SM diet supplemented with different levels of C-I20 (320, 160, 80, 40, 0 mg/Kg) for 10 weeks. 160 mg/Kg C-I20 treatment significantly improved the final body weight, weight gain rate and crude protein content of mandarin fish and reduced feed conversion ratio. 160 mg/Kg C-I20-fed fish maintained appropriate goblet cells number and mucin thickness, as well as improved villus length, intestinal cross-sectional area. Based on these advantageous physiological changes, 160 mg/Kg C-I20 treatment effectively reduced multi-type tissue (liver, trunk kidney, head kidney and spleen) injury. The addition of C-I20 did not change the muscle composition and muscle amino acids composition. Interestingly, dietary 160 mg/Kg C-I20 supplementation prevented the reduction in myofiber diameter and change in muscle texture, and effectively increased polyunsaturated fatty acids (especially DHA + EPA) in muscle. In conclusion, dietary C-I20 in a reasonable concentration supplementation effectively alleviates the negative effects of SM by improving the intestinal mucosal barrier. The application of nanopeptide C-I20 is a prospectively novel strategy for promoting aquaculture development.

Engineered hydrogels for peripheral nerve repair

Peripheral nerve injury (PNI) is a complex disease that often appears in young adults. It is characterized by a high incidence, limited treatment options, and poor clinical outcomes. This disease not only causes dysfunction and psychological disorders in patients but also brings a heavy burden to the society. Currently, autologous nerve grafting is the gold standard in clinical treatment, but complications, such as the limited source of donor tissue and scar tissue formation, often further limit the therapeutic effect. Recently, a growing number of studies have used tissue-engineered materials to create a natural microenvironment similar to the nervous system and thus promote the regeneration of neural tissue and the recovery of impaired neural function with promising results. Hydrogels are often used as materials for the culture and differentiation of neurogenic cells due to their unique physical and chemical properties. Hydrogels can provide three-dimensional hydration networks that can be integrated into a variety of sizes and shapes to suit the morphology of neural tissues. In this review, we discuss the recent advances of engineered hydrogels for peripheral nerve repair and analyze the role of several different therapeutic strategies of hydrogels in PNI through the application characteristics of hydrogels in nerve tissue engineering (NTE). Furthermore, the prospects and challenges of the application of hydrogels in the treatment of PNI are also discussed.

Substance P&dimethyloxallyl glycine-loaded carboxymethyl chitosan/gelatin hydrogel for wound healing

Recent efforts have focused on preparing drug-loaded hydrogel for wound healing. In order to obtain an ideal hydrogel dressing for skin wound repair, a carboxymethyl chitosan-gelatin hydrogel was prepared for co-delivery of SP (substance P) and DMOG (dimethyloxallyl glycine) by a chemical cross-linking method using genipin as the cross-linking agent. The synthesized hydrogels have good biocompatibility and physicochemical properties due to the low toxicity of the hydrogel material. The three-dimensional network structure of the hydrogels supports cell migration and proliferation, and the combination of SP and DMOG drugs exhibited strong effects on cell proliferation. Moreover, the co-loaded drug hydrogels could significantly promote wound healing in vivo, and provide a potential hydrogel for wound healing.

Synthesis characterisation and neuroprotectivity of Silybum marianum extract loaded chitosan nanoparticles

AIM

Silybum marianum extract (SME) possesses neuroprotective potency through its high antioxidant content. We attempted to increase the effectiveness of SME by encapsulating them in chitosan. Neuroprotective potency of SME and SME-loaded chitosan nanoparticles (SME-CNPs) were shown in SH-SY5Y cell line against H₂O₂-induced oxidative stress.

METHODS

We produced CNPs and SME-CNPs by ionic gelation method and properly determined their physical characteristics. Encapsulation efficiency, loading capacity, and in vitro release tests were performed for SME-CNPs. The neurotoxicity and neuroprotective efficiency in SH-SY5Y cell line against H₂O₂ was also investigated.

RESULTS

The size of SME-CNPs was 168.2 ± 11.12 nm with zeta potential 10.6 ± 1.0 mV. The encapsulation efficiency and loading capacity were successfully achieved at 96.6% and 1.89% respectively. SME and SME-CNPs improved cell viability higher than 80%, and SME-CNPs exhibited significant neuroprotective effects against H₂O₂ damage.

CONCLUSIONS

It was concluded that SME and SME-CNPs highly prevent damage caused by H₂O₂ and reduce cell damage in vitro by their neuroprotective effects.

Effect of Carboxymethyl Chitin on Capsule Formation around Silicone Implants: An In Vivo and In Vitro Study

BACKGROUND

Capsular contracture is a serious complication that occurs after augmentation mammaplasty. The authors previously identified that carboxymethyl chitin had an inhibitory effect on capsule formation. This study was performed to elucidate the possible molecular mechanisms through which carboxymethyl chitin inhibits the formation of a capsule around silicone implants.

METHODS

In this study, the authors cultured human dermal fibroblasts and treated them with carboxymethyl chitin in vitro. The difference in proliferation between treated and untreated cells was analyzed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Protein levels of transforming growth factor beta-1 and alpha smooth muscle actin (α-SMA) were examined by Western blot analysis. Expression levels of type I and type III collagen were checked by enzyme-linked immunosorbent assay. In vivo, silicone implants were placed under the pectoralis muscle in 12 female rabbits. The thickness of the capsule was measured by histologic analysis, and the effect of carboxymethyl chitin on α-SMA, collagen type I and III expression levels was evaluated by real-time polymerase chain reaction analysis, enzyme-linked immunosorbent assay, Western blot, and immunofluorescence analysis.

RESULTS

In the in vitro study, we confirmed that carboxymethyl chitin inhibited the proliferation of fibroblasts. The protein expression levels of collagen type I, transforming growth factor beta-1, and α-SMA were inhibited by carboxymethyl chitin treatment. In vivo, carboxymethyl chitin treatment reduced capsular thickness and the expression of α-SMA and collagen types I and III in capsules around silicone implants.

CONCLUSION

The authors' results showed that carboxymethyl chitin could influence capsule formation around silicone implants by inhibiting the fibroblast activity, interrupting fibroblast-to-myofibroblast differentiation, and decreasing collagen synthesis.

CLINICAL RELEVANCE STATEMENT

Carboxymethyl chitin influence capsule formation around silicone implants. Although more clinical studies are needed to verify the effect of carboxymethyl chitin on capsular contracture, the authors believe that it will play an effective role in the clinical application of reducing the occurrence of capsular contracture.

Carboxymethyl chitosan prolongs adenovirus-mediated expression of IL-10 and ameliorates hepatic fibrosis in a mouse model

Effective and safe liver-directed gene therapy has great promise in treating a broad range of liver diseases. While adenoviral (Ad) vectors have been widely used for efficacious in vivo gene delivery, their translational utilities are severely limited due to the short duration of transgene expression and solicitation of host immune response. Used as a promising polymeric vehicle for drug release and nucleic acid delivery, carboxymethyl chitosan (CMC) is biocompatible, biodegradable, anti-microbial, inexpensive, and easy accessible. Here, by exploiting its biocompatibility, controlled release capability and anti-inflammatory activity, we investigated whether CMC can overcome the shortcomings of Ad-mediated gene delivery, hence improving the prospect of Ad applications in gene therapy. We demonstrated that in the presence of optimal concentrations of CMC, Ad-mediated transgene expression lasted up to 50 days after subcutaneous injection, and at least 7 days after intrahepatic injection. Histologic evaluation and immunohistochemical analysis revealed that CMC effectively alleviated Ad-induced host immune response. In our proof-of-principle experiment using the CCl4-induced experimental mouse model of chronic liver damage, we demonstrated that repeated intrahepatic administrations of Ad-IL10 mixed with CMC effectively mitigated the development of hepatic fibrosis. Collectively, these results indicate that CMC can improve the prospect of Ad-mediated gene therapy by diminishing the host immune response while allowing readministration and sustained transgene expression.

Berberine coated biocomposite hemostatic film based alginate as absorbable biomaterial for wound healing

In wound treatment, severe bleeding and infection are always primary challenges. Therefore, it is highly desired to develop novel dressing with both hemostatic and antibacterial capability. Herein, a series of biocomposite hemostatic films (BHFs) based alginate/chitosan/collagen-berberine have been prepared and well characterized for further biofunctional study. We have demonstrated that the hemostatic and antibacterial activities were significantly enhanced by calcium/berberine dual-crosslinking system in the film. Through the synergistic effects, BHF-6B exhibited a shorter in vivo clotting and wound healing time than that of commercial dressing in rat tail amputation and full-thickness skin defect models. Additionally, BHF-6B showed excellent bacteriostatic activity with long-term effects. Moreover, hemolysis and cytotoxicity tests in vitro illustrated the prominent biocompatibility of the composite films. Notably, BHF-6B could be degraded quickly and completely in vivo. Overall, the present work indicated that the functionalized BHF-6B has great potential as an absorbable biomaterial for wound treatment.

Recent Advances in Chitosan and its Derivatives in Cancer Treatment

Cancer has become a main public health issue globally. The conventional treatment measures for cancer include surgery, radiotherapy and chemotherapy. Among the various available treatment measures, chemotherapy is still one of the most important treatments for most cancer patients. However, chemotherapy for most cancers still faces many problems associated with a lot of adverse effects, which limit its therapeutic potency, low survival quality and discount cancer prognosis. In order to decrease these side effects and improve treatment effectiveness and patient’s compliance, more targeted treatments are needed. Sustainable and controlled deliveries of drugs with controllable toxicities are expected to address these hurdles. Chitosan is the second most abundant natural polysaccharide, which has excellent biocompatibility and notable antitumor activity. Its biodegradability, biocompatibility, biodistribution, nontoxicity and immunogenicity free have made chitosan become a widely used polymer in the pharmacology, especially in oncotherapy. Here, we make a brief review of the main achievements in chitosan and its derivatives in pharmacology with a special focus on their agents delivery applications, immunomodulation, signal pathway modulation and antitumor activity to highlight their role in cancer treatment. Despite a large number of successful studies, the commercialization of chitosan copolymers is still a big challenge. The further development of polymerization technology may satisfy the unmet medical needs.

Carboxymethyl chitosan-based electrospun nanofibers with high citral-loading for potential anti-infection wound dressings

As a natural antibacterial agent with pleasant fragrance, citral possesses low aqueous solubility. To improve citral loading in hydrophilic nanofiber, Pickering emulsion electrospinning strategy was proposed for anti-infection dressing development. The in-situ aggerated β-cyclodextrin-citral inclusion complex particles (βCPs) were used as emulsion stabilizers, while citral and carboxymethyl chitosan (CMCS)/polyvinyl alcohol (PVA) mixed solutions were used as the inner "dispersed oil phase" and outer "continuous water phase", respectively. The results of electronic microscope investigation shown βCPs possessed regular cube appearances with a size of 5.5 ± 2.2 μm, which might improve the emulsion storage stability based on visual investigation. Moreover, randomly oriented and bead-on-string nanofibers with βCPs uniformly distributed could be obtained under optimized compositions and electrospinning parameters. Despite volatilization during electrospinning, nanofibers with high citral loading possessed good antibacterial performance against Staphylococcus aureus and Escherichia coli. In vitro hemolysis test indicated that nanofibers were hemocompatible. In addition, both fiber matrix and citral could promote the proliferation of mouse fibroblast cells. And the permeability of the fibers was adjustable. Thus, CMCS/PVA/βCPs/citral nanofibers could potentially protect wound from infection. In summary, CMCS/PVA/βCPs/citral nanofibers seemed to be promising alternatives to conventional wound dressings.

Oral Administration of Nanopeptide CMCS-20H Conspicuously Boosts Immunity and Precautionary Effect Against Bacterial Infection in Fish

Massive mortalities caused by bacterial infections in intensive aquaculture result in serious economic losses. In this study, a novel antimicrobial peptide gcIFN-20H was efficiently expressed in Pichia pastoris (GS115) and loaded on carboxylmethyl chitosan (CMCS) to prepare CMCS-20H nanoparticles. Through physical characterization assays (TEM, DLS, BCA, and Raman) and biological activity tests (antimicrobial activity and cytotoxicity), CMCS-20H nanopeptide was verified to be spherical nanoparticles with sustained release, antimicrobial activity, and negligible toxicity. CMCS-20H nanoparticles are more resistant to intestinal degradation than unloaded gcIFN-20H by indirect immunofluorescence assay. Oral administration was then carried out for 42 days. Complement C3 content, lysozyme, and total superoxide dismutase activities are highest in CMCS-20H group by serum biochemistry index assays. After challenge with Aeromonas hydrophila, the survival rate in CMCS-20H group is highest (46%), which is 64% higher than the control group (28%). Meanwhile, the tissue bacterial loads (intestine, spleen, head kidney, trunk kidney, hepatopancreas, muscle, and blood) in the CMCS-20H group are significantly lower than other groups. By PAS staining analysis, the number of intestinal villi goblet cells and the thickness of mucin in the CMCS-20H group obviously increased. CMCS-20H effectively enhances mRNA expressions of some important immune genes (IL-1β, IL-6, TNF-α, IL-2, IFN-γ2, and IgM). The minimal tissue lesions (Intestine, spleen, and trunk kidney) were seen in the CMCS-20H group by histopathological examination. 16S rRNA sequencing showed that oral CMCS-20H maintains the intestinal microbiome homeostasis in bacterial infection. The results indicate that the novel nanopeptide CMCS-20H as the immunopotentiator can remarkably boost fish immunity and precautionary effect by oral administration and address the theoretical mechanisms and insights into the promising application prospect in aquaculture.

In-situ silver nanoparticles incorporated N, O-carboxymethyl chitosan based adhesive, self-healing, conductive, antibacterial and anti-biofilm hydrogel

Hydrogels are excellent wound healing materials. However, due to the wear and tear at the wound site, hydrogels can lose their structural and functional integrity. To overcome this and to effectively seal the wound and control infection, an in-situ silver nanoparticles (AgNps) incorporated N, O-carboxymethyl chitosan (N, O-CMC) based self-healing hydrogel using ethylenediaminetetraacetic acid-ferric ion (EDTA: Fe³⁺) complex was developed. The prepared N, O-CMC/AgNps hydrogel was characterized using FTIR, SEM, and TEM. The developed N, O-CMC/AgNps hydrogel was found to be adhesive, injectable, conductive, bio-compatible, and showed antibacterial activity against ATCC and clinical strains of E. coli, K. pneumonia, P. aeruginosa, S. aureus and MRSA. N, O-CMC/AgNps hydrogel also showed anti-biofilm activity against S. aureus, E. coli, and P. aeruginosa (ATCC strains). This developed antibacterial and self-healing N, O-CMC/AgNps hydrogel can be used in the treatment of infected wounds.

Orally Administrable Therapeutic Nanoparticles for the Treatment of Colorectal Cancer

Colorectal cancer (CRC) is one of the most common and lethal human malignancies worldwide; however, the therapeutic outcomes in the clinic still are unsatisfactory due to the lack of effective and safe therapeutic regimens. Orally administrable and CRC-targetable drug delivery is an attractive approach for CRC therapy as it improves the efficacy by local drug delivery and reduces systemic toxicity. Currently, chemotherapy remains the mainstay modality for CRC therapy; however, most of chemo drugs have low water solubility and are unstable in the gastrointestinal tract (GIT), poor intestinal permeability, and are susceptible to P-glycoprotein (P-gp) efflux, resulting in limited therapeutic outcomes. Orally administrable nanoformulations hold the great potential for improving the bioavailability of poorly permeable and poorly soluble therapeutics, but there are still limitations associated with these regimes. This review focuses on the barriers for oral drug delivery and various oral therapeutic nanoparticles for the management of CRC.

Targeted Drug Delivery Systems for Kidney Diseases

Kidney diseases have gradually become a global health burden. Along with the development of nanotechnology, many hybrids or nanomaterials have been utilized to promote treatment efficiency with negligible side effects. These therapeutic agents have been successfully applied in many fields. In particular, some efforts have also been made to ameliorate the treatment of kidney diseases through targeted delivery nanomaterials. Though most of the delivery systems have not yet been transmitted into clinical use or even still at an early stage, they have shown great potential in carrying immunosuppressants like tacrolimus and triptolide, antioxidants, or siRNAs. Excitingly, some of them have achieved significant treatment effectiveness and reduced systemic side effect in kidney disease animal models. Here, we have reviewed the recent advances and presented nanotherapeutic devices designed for kidney targeted delivery.

Oleogel Films Through the Pickering Effect of Bacterial Cellulose Nanofibrils Featuring Interfacial Network Stabilization

As bio-based food packaging materials promise a more sustainable future, this work fabricated edible oleofilms by casting beeswax-in-water Pickering emulsions, which were formed by the physical hybrid particles of bacterial cellulose nanofibrils (BCNFs) and carboxymethyl chitosan (CCS) (BC/CCS). The emulsion droplet size was varied from 4 to 9 μm, and the emulsion index (EI) was all up to 100%. The obtained emulsions exhibited excellent long-term stability, and there was no change in the EI (100%) after the storage of the emulsion for 3 months. Moreover, the environmental temperature had almost no impact on the droplet size and EI of the emulsion. The mechanical properties of the oleofilms were significantly improved by enhancing the content of BC/CCS. There was also a visual reduction in the water vapor permeability (WVP) value, which was lower than 1.1 × 10^-7 g·m^-1·h^-1·Pa^-1. Furthermore, the obtained oleofilms exhibited a notable improvement in surface hydrophobicity, and surprisingly, it could be easily redispersed into water to recover back to the emulsion state without additional high energy mixing. This suggested that this edible oleofilm was prepared by a fully green method by casting Pickering emulsions stabilized by BC/CCS and could extend its application for the development of food-grade coating materials.

Chitin and its derivatives: Structural properties and biomedical applications

Chitin, a polysaccharide that occurs abundantly in nature after cellulose, has attracted the interest of the scientific community due to its plenty of availability and low cost. Mostly, it is derived from the exoskeleton of insects and marine crustaceans. Often, it is insoluble in common solvents that limit its applications but its deacetylated product, named chitosan is found to be soluble in protonated aqueous medium and used widely in various biomedical fields. Indeed, the existence of the primary amino group on the backbone of chitosan provides it an important feature to modify it chemically into other derivatives easily. In the present review, we present the structural properties of chitin, and its derivatives and highlighted their biomedical implications including, tissue engineering, drug delivery, diagnosis, molecular imaging, antimicrobial activity, and wound healing. We further discussed the limitations and prospects of this versatile natural polysaccharide.

Targeted Antitumor Mechanism of C-PC/CMC-CD55sp Nanospheres in HeLa Cervical Cancer Cells

In vitro studies had shown that C-Phycocyanin (C-PC) inhibited cervical cancer HeLa cells growth. We constructed C-PC/CMC-CD55sp nanospheres using C-PC, Carboxymethyl Chitosan (CMC), and CD55 ligand peptide (CD55sp) to allow for targeted antitumor effects against HeLa cells in vitro and in vivo. The characteristics of the nanospheres were determined using FTIR, electron microscopy, and laser particle size analysis. Flow cytometry, laser confocal microscopy and small animal imaging system showed the targeting of C-PC/CMC-CD55sp nanospheres on HeLa cells. Subsequently, the proliferation and apoptosis were analyzed by Cell Counting Kit-8 (CCK-8), flow cytometry, TUNEL assay and electron microscopy. The expression of the apoptosis-related protein was determined using western blot. The stainings of Hematoxylin and Eosin (HE) were employed to evaluate the cell condition of tumor tissue sections. The cytokines in the blood in tumor-bearing nude mice was determined using ELISA. These results showed that C-PC/CMC-CD55sp nanospheres were successfully constructed and targeted HeLa cells. The constructed nanospheres were more effective than C-PC alone in inhibiting the proliferation and inducing apoptosis in HeLa cells. We also found that C-PC/CMC-CD55sp nanospheres had a significant inhibitory effect on the expression of antiapoptotic protein Bcl-2 and a promotion on the transformation of caspase 3 to cleaved caspase 3. C-PC/CMC-CD55sp nanospheres played an important role in tumor suppression, reduced the expression TGF-β, and increased IL-6 and TNF-α. This study demonstrates that the constructed new C-PC/CMC-CD55sp nanospheres exerted targeted antitumor effects in vivo and in vitro which provided a novel idea for application of C-PC, and provided experimental basis for comprehensive targeted treatment of tumors.

A Brief Review of Edible Coating Materials for the Microencapsulation of Probiotics

The consumption of probiotics has been associated with a wide range of health benefits for consumers. Products containing probiotics need to have effective delivery of the microorganisms for their consumption to translate into benefits to the consumer. In the last few years, the microencapsulation of probiotic microorganisms has gained interest as a method to improve the delivery of probiotics in the host as well as extending the shelf life of probiotic-containing products. The microencapsulation of probiotics presents several aspects to be considered, such as the type of probiotic microorganisms, the methods of encapsulation, and the coating materials. The aim of this review is to present an updated overview of the most recent and common coating materials used for the microencapsulation of probiotics, as well as the involved techniques and the results of research studies, providing a useful knowledge basis to identify challenges, opportunities, and future trends around coating materials involved in the probiotic microencapsulation.

High-Strength Physically Multi-Cross-Linked Chitosan Hydrogels and Aerogels for Removing Heavy-Metal Ions

With the goal of improving the mechanical strength of chitosan hydrogels, gallic acid modified carboxymethyl chitosan/iron ion (GA-CMCS/Fe^III) complex hydrogels were initially prepared via noncovalent interactions and metal coordination. ¹H NMR, ¹³C NMR, and Fourier trantsform infrared spectra analysis confirmed the covalent reactions between CMCS and GA. The formation of GA-CMCS hydrogel occurred through electrostatic interactions, hydrogen bonds, and hydrophobic interactions. GA-CMCS/Fe^III hydrogel (380 kPa) exhibited higher compressive strength than GA-CMCS hydrogel (315 kPa). In addition, GA-CMCS/Fe^III aerogel displayed satisfactory mechanical strength (1.59 MPa) and high-efficiency adsorption capacities up to 97.15 mg/g for Pb²⁺, 99.75 mg/g for Cd²⁺, and 98.50 mg/g for Cu²⁺, respectively. In addition, both of the GA-CMCS and GA-CMCS/Fe^III aerogel adsorbents exhibited satisfactory recyclability. The design of GA-CMCS and GA-CMCS/Fe^III hydrogels and aerogels offers a new opportunity for the construction of physically multi-cross-linked systems with excellent mechanical properties.

A Novel Method to Increase Tumor Ablation Zones With RFA by Injecting the Cationic Polymer Solution to Tissues: In Vivo and Computational Studies

OBJECTIVE

This study aims to examine, for the first time, the introduction of cationic polymer solutions to improve radiofrequency ablation (RFA) in terms of a potentially enlarged ablation zone.

METHODS

By using in vivo and computational RFA studies, two cationic polymers, Chitooligosaccharides (COS) and carboxymethyl chitosan (CMC), diluted in deionized water, were injected into tissues separately surrounding the RF bipolar electrode prior to power application. A total of 9 rabbits were used to 1) measure the increase in electrical conductivity of tissues injected with the cationic polymer solutions, and 2) explore the enhancement of the ablation performance in RFA trials. A computer model of RFA comprising a model of the solution diffusion with an RF thermal ablation model was also built, validated by the in vivo experiment, to quantitatively study the effect of cationic polymer solutions on ablation performances.

RESULTS

Compared to the control group, the electrical conductivity of rabbit liver tissues was increased by 42.20% (0.282 ± 0.006 vs. 0.401 ± 0.048 S/m, P = 0.001) and 43.97% (0.282 ± 0.006 vs. 0.406 ± 0.042 S/m, P = 0.001) by injecting the COS and CMC solution at the concentration of 100 mg/mL into the tissues, denoted COS_DW100 and CMC_DW100, respectively. Consequently, the in vivo experiments show that the ablation zone was enlarged by 95% (47.6 ± 6.3 vs. 92.6 ± 11.5 mm², P < 0.001) and 87% (47.6± 6.3 vs. 88.8 ± 9.6 mm², P < 0.001) by COS_DW100 and CMC_DW100, respectively. The computer simulation shows that the ablation zone was enlarged by 71% (51.9 vs. 88.7 mm²) and 63% (51.9 vs. 84.7 mm²) by COS_DW100 and CMC_DW100, respectively.

CONCLUSION

The injection of the cationic solution can greatly improve the performance of RFA treatment in terms of enlarging the ablation zone, which is due to the increase in the electrical conductivity of liver tissues surrounding the RF electrode.

SIGNIFICANCE

This study contributes to the improvement of RFA in the treatment of large tumors.

Advances in chitosan-based nanoparticles for oncotherapy

Chitosan has attracted considerable attention as an anti-tumor drug carrier material in recent years, which is due to its biocompatibility and biodegradability, as well as the simple and mild preparing techniques of drug-loaded nanoparticles. Chitosan-based nanoparticles can deliver various anti-tumor agents to specific tumor tissues by passive and active targeting mechanisms, including traditional chemotherapeutic agents, DNA or siRNA, proteins, photosensitizers and so on. In this review, we summarized the factors affecting the anti-tumor efficacy of chitosan-based nanoparticles, to aid exploring the function-structure relationship. The recent studies on chitosan-based nanoparticles for oncotherapy were highlighted, including their structures, properties and pharmacological effects. Finally, we offered our perspectives on the challenges and future development of this area.

Biosynthesis and characterization of hydroxyapatite and its composite (hydroxyapatite-gelatin-chitosan-fibrin-bone ash) for bone tissue engineering applications

Hydroxyapatite (HAp) is a bioactive and biocompatible material possessing osteoconductive properties used widely in the biomedical sector. In the present study, synthesis of hydroxyapatite (HAp) using a Klebsiella pneumoniae SM24 (phosphate solubilizing bacteria) isolated from the slaughterhouse. HAp synthesized using biological source showed efficient and positive enzymatic activity in the National Botanical Research Institute Phosphate Medium (NBRIP). Characterization of HAp using FTIR revealed the presence of phosphate group hydroxyapatite and XRD spectra showed polycrystalline nature. The morphological characterization of HAp using FESEM revealed the mesoporous structure and EDX spectrum indicated presence of Ca and P as the major components. In addition, a new bone composite was prepared using the synthesized HAp, Gelatine (G), Chitosan (C), Fibrin (F) and Bone ash (HApGCF) using Simulated Body Fluid (SBF) solution. The confirmation of chemical and structural characteristics of HApGCF bone composite was achieved using FTIR, XRD and SEM analyses. The HApGCF bone composite was tested over osteoblast MG-63 cells showing effective biocompatibility and osteoblast attachment on the composite surface. Therefore, the present report proposes the in vitro application of HApGCF bone composite as a replacement for major bone damage and injury in a biocompatible and non-toxic way.

Biodegradable and electroconductive poly(3,4-ethylenedioxythiophene)/carboxymethyl chitosan hydrogels for neural tissue engineering

Electroconductive hydrogels with excellent electromechanical properties have become crucial for biomedical applications. In this study, we developed a conductive composite hydrogel via in-situ chemical polymerization based on carboxymethyl chitosan (CMCS), as a biodegradable base macromolecular network, and poly(3,4-ethylenedioxythiophene) (PEDOT), as a conductive polymer layer. The physicochemical and electrochemical properties of conductive hydrogels (PEDOT/CMCS) with different contents of PEDOT polymer were analyzed. Cell viability and proliferation of neuron-like rat phaeochromocytoma (PC12) cells on these three-dimensional conductive hydrogels were evaluated in vitro. As results, the prepared semi-interpenetrating network hydrogels were shown to consist of up to 1825±135wt% of water with a compressive modulus of 9.59±0.49kPa, a porosity of 93.95±1.03% and an electrical conductivity of (4.68±0.28)×10^-3S·cm^-1. Cell experiments confirmed that PEDOT/CMCS hydrogels not only had no cytotoxicity, but also supported cell adhesion, viability and proliferation. These results demonstrated that the incorporation of conductive PEDOT component into CMCS hydrogels endowed the hydrogels with enhanced mechanical strength, conductivity and kept the biocompatibility. Thus, the attractive performances of these composite hydrogels would make them suitable for further neural tissue engineering application, such as nerve regeneration scaffold materials.

Valorisation of chitinous biomass for antimicrobial applications

The chitin and chitosan market worldwide has shown tremendous growth, propelled by the expansion in the application domain. The market volume is projected to be more than 155 thousand metric tons by the year 2022. The global market for chitin and chitosan derivatives is expected to reach $4.2 billion by 2021 up from $2.0 billion in 2016 at a compound annual growth rate (CAGR) of 15.4%, from 2016 to 2021. Among chitin derivatives, chitosan is projected to offer the highest growth potential. The demand for a reliable source of high quality chitosan is rapidly increasing as new value added products enter the market. At the same time the growth of value added chitosan based products are limited by the availability of a sustainable supply chain. Antimicrobial properties are of special interest in the packaging, cosmetic, food and biomedical sector. Most of the latter applications warrants high-volume and low cost materials. However, the process chemistry for bulk chitosan manufacturing is currently not very environmentally friendly. Green technologies for chitosan modification have increased in recent years and now face the challenge of economic viability. In this review the status of antimicrobial chitosan derivatives will be reported with a critical review of the chemical technologies that would mitigate the commercialisation of these biopolymers in the antimicrobial biopolymer market sector. The amount of publications per annum has increased exponentially and the lack of global standardised antimicrobial test protocols make it rather challenging to properly evaluate the relative efficacy of these polymers.

The Targeted Antitumor Effects of C- PC/CMC-CD59sp Nanoparticles on HeLa Cells in Vitro and in Vivo

The novel C-PC/CMC-CD59sp-NPs were made by carbocymethyl chitosan (CMC) loading C-phycocyanin (C-PC) with the lead of CD59 specific ligand peptide (CD59sp) for targeting, and the characteristics and targeted anti-tumor mechanism were explored in order to realize the targeted therapy of C-PC on the growth of HeLa cells both in vitro and vivo. The targeting nanoparticles were synthesized by ionic-gelation method, and the optimal condition was selected out by orthogonal analysis. The properties of nanoparticles were observed by laser particle analyzer and dynamic light scattering (DLS) and Fourier Transform Infrared Spectrometer (FTIR). The effects of nanoparticles on the proliferation of HeLa cells in vitro were assessed by MTT assay. The mice model with tumor was constructed by subcutaneous injection of HeLa cells into the left axilla of NU/NU mice. The weight of tumor and the spleen were tested. The expression quantities of cleaved caspase-3, Bcl-2 were determined by western blot and immunofluorescent staining. Results showed the morphology of the finally prepared nanoparticles was well distributed with a diameter distribution of 200±11.3 nm and zeta potential of -19.5±4.12mV. Under the guidance of CD59sp, the targeting nanoparticles could targetedly and efficiently arrive at the surface of HeLa cells, and had obvious inhibitory effect on HeLa cells proliferation both in vitro and vivo. Moreover, the nanoparticles could induce cell apoptosis by up-regulation of cleaved caspase-3 proteins expression, but down-regulation of Bcl-2 and cyclinD1 proteins. Our study provided a new idea for the research and development of marine drugs, and supplied a theoretical support for the target therapy of anticancer drug.

Carboxymethyl chitosan nanoparticles coupled with CD59-specific ligand peptide for targeted delivery of C-phycocyanin to HeLa cells

The combination of nanotechnology and medicine will be the next generation of vehicles for targeted drug delivery. Carboxymethyl chitosan loaded with the anticancer drug C-phycocyanin and the CD59-specific ligand peptide for cancer cell targeting were used to create C-phycocyanin/carboxymethyl chitosan-CD59-specific ligand peptide nanoparticles using the ionic-gelation method. Optimal synthesis conditions, selected by response surface methodology, comprised the ratio carboxymethyl chitosan:C-phycocyanin = 3:1, and carboxymethyl chitosan and CaCl₂ concentrations of 2.0 and 1.0 mg/mL, respectively. The resulting nanoparticles were spherical, with diameters of approximately 200 nm; the entrapment efficient was about 65%; and the drug loading was about 20%. The release of C-phycocyanin from C-phycocyanin/carboxymethyl chitosan nanoparticles was pH sensitive and had a sustainable effect in vitro. Guided by the CD59-specific ligand peptide, the nanoparticles efficiently targeted the surface of HeLa cells and had an obvious inhibitory effect on HeLa cell proliferation as determined by methyl thiazolyl tetrazolium assays. The nanoparticles were hemocompatible and induced apoptosis by upregulation of cleaved caspase-3 and cleaved polyADP-ribose polymerase proteins, and downregulation of Bcl-2 proteins. Our study provides a novel approach to the research and development of marine drugs, and support for targeted therapy using anticancer drugs.

Statins anticancer targeted delivery systems: re-purposing an old molecule

OBJECTIVES

Exploring the use of statins as anticancer agents and exploiting different drug delivery systems in targeting these molecules to cancerous sites. Literature review was performed to investigate the use of statins in cancer treatment in one hand, and the different pharmaceutical approaches to deliver and target these drugs to their site of action.

KEY FINDINGS

Statins were used for decades as antihypercholestrolemic drugs but recently have been proven potential for broad anticancer activities. The incorporation of statins in nanoparticulate drug delivery systems not only augmented the cytotoxicity of statins but also overcame the resistance of cancerous cells against the traditional chemotherapeutic agents. Statins-loaded nanoparticles could be easily tampered to target the cancerous cells and consequently minimal drug amount could be utilized.

SUMMARY

This review reconnoitered the different endeavors to incorporate statins in various nanoparticles and summarized the successful effects in targeting cancerous cells and reducing their proliferation without the side effects of commonly used chemotherapeutic agents.

GENDER INFLUENCES DIFFERENTIATION OF CHITIN AMONG BODY PARTS

Earlier reports have established that chitin isolates from each body part of an insect cuticle can exhibit diverse physicochemical properties. But it is still unknown if the gender of the insect can influence characteristics of chitin isolates from different body parts. The present study addresses this question. As a result, important physicochemical differences in the chitin samples from different body parts of Melolontha sp. were recorded on the basis of sex. The chitin samples were extracted from eight different body parts (antennae, head, eyes, thorax, abdomen, elytra, hindwings, and legs) of female and male. The most remarkable variations in the chitin isolates from female and male body parts were recorded in chitin content, crystallinity, thermal stability, and surface morphology. And also it was wondered these chitin isolates from different body parts of female and male could find different applications. To check this hypothesis, the chitin samples from female and male were interacted with bovine serum albumin (BSA) protein and important variations were observed.

Cisplatin-crosslinked glutathione-sensitive micelles loaded with doxorubicin for combination and targeted therapy of tumors

The delivery of combination chemotherapy by nanoscale platforms has been demonstrated to enhance cancer treatment in the clinic. Cisplatin (CDDP)-crosslinked, glutathione-sensitive, tumor-targeting micelles based on carboxymethyl chitosan were designed for synergistic cisplatin-doxorubicin (DOX) combination chemotherapy. In our study, DOX was conjugated to carboxymethyl chitosan through a disulfide bond, which was structurally characterized by ¹H NMR. The micelles formed by self-assembly were spherical, with the mean diameter of 274nm. The in vitro release studies revealed that the micelles were highly glutathione-sensitive. Cytotoxicity analysis demonstrated that the cisplatin-crosslinked micelles loaded with DOX exhibited enhanced therapeutic efficacy compared with the DOX-loaded nanoparticles, free DOX, and free CDDP. Cellular uptake and intracellular release revealed that the cisplatin-crosslinked micelles loaded with DOX could efficiently deliver and release DOX into the cancer cells. These results clearly indicate that tumor-targeting and glutathione-sensitive micelles provide means for combination drug delivery in cancer treatment.

A unique highly hydrophobic anticancer prodrug self-assembled nanomedicine for cancer therapy

In contrast with common thought, we generated highly hydrophobic anticancer prodrug self-assembled nanoparticles without the aid of surface active substances, based on the conjugation of docetaxel to d-α-tocopherol succinate. The reduction-sensitive prodrug was synthesized with a disulfide bond inserted into the linker and was compared with a control reduction-insensitive prodrug. The morphology and stability of self-assembled nanoparticles were investigated. Cytotoxicity and apoptosis assays showed that the reduction-sensitive nanoparticles had higher anticancer activity than the reduction-insensitive nanoparticles. The reduction-sensitive nanoparticles exhibited favorable in vivo antitumor activity and tolerance compared with docetaxel Tween80-containing formulation and the reduction-insensitive nanoparticles. Taken together, the unique nanomedicine demonstrated a number of advantages: (i) ease and reproducibility of preparation, (ii) high drug payload, (iii) superior stability, (iv) prolonged circulation, and (v) improved therapeutic effect. This highly reproducible molecular assembly strategy should motivate the development of new nanomedicines.

Dibutyrylchitin nanoparticles as novel drug carrier

Chitin is a ubiquitous renewable biopolymer that is significantly distributed in the natural world. Biopolymeric nanoparticles (Nps) have been developed for various biomedical applications by researchers. Here, chitin derivative, dibutyrylchitin Nps (DBC) was synthesized as a nanocarrier for drug delivery using butyric anhydride and perchloric acid as a catalyst under heterogeneous conditions. The structural characterization was analyzed by FT-IR and FE SEM study showed spherical particles in a size range of 80-90 nm. The physiochemical evaluation involves swelling behavior and in vitro biodegradation studies. The results of in vitro hemolytic assay validate the blood compatibility of the prepared system. Drug release profiles indicate that 5-flourouracil (Fu) loaded dibutyrylchitin Nps (DBC-Fu) gives the enhanced drug release in acidic pH when compared to neutral pH. The encapsulation efficiency of DBC-Fu was found to be 90%. The confocal analysis also confirmed the uptake of both DBC and DBC-Fu Nps by A549 cell lines. Hence, this study shows that the DBC have the potential to be used as a drug carrier and also for other biomedical applications.

Current progress in nanotechnology applications for diagnosis and treatment of kidney diseases

Significant progress has been made in nanomedicine, primarily in the form of nanoparticles, for theranostic applications to various diseases. A variety of materials, both organic and inorganic, have been used to develop nanoparticles with promise to achieve improved efficacy in medical applications as well as reduced systemic side effects compared to current standard of care medical practices. In particular, this article highlights the recent development and application of nanoparticles for diagnosing and treating nephropathologies.