Synthesis of BLF1-containing trimethyl chitosan nanoparticles and evaluation of its immunogenicity and protection in syrian mice by oral and subcutaneous injections.

The bacterium Burkholderia pseudomallei is the cause of melioidosis infectious disease. In this bacterium, the BLF1 protein wide inhibits the synthesis of proteins in human cells. This disease is reported to cause a death rate of 40% in some parts of the world. Currently, no effective vaccine is available against this bacterial infection. In this study, therefore, a Nano vaccine was synthesized based on the trimethyl chitosan (TMC) polymer containing the BLF1 recombinant protein, and its immunogenicity and protection in Syrian mice were evaluated by oral and subcutaneous injections. The BLF1 recombinant protein expression was induced in Escherichia coli Bl21 (DE3) and purified by the affinity chromatography technique. Recombinant protein-containing nanoparticles (NPs) were then synthesized by the ionotropic gelation method. After oral and subcutaneous injections, antibody titration was assessed by the indirect ELISA assay. Finally, murine groups were challenged using the BLF1 toxin. The results indicated that the immune system showed more antibody titration in subcutaneous injection than in the oral form. However, the results were reversed in the challenge results, and the survival rate was more significant in the oral injection.

Antiseptic, Hemostatic, and Wound Activity of Poly(vinylpyrrolidone)-Iodine Gel with Trimethyl Chitosan.

Wound management practices have made significant advancements, yet the search for improved antiseptics persists. In our pursuit of solutions that not only prevent infections but also address broader aspects of wound care, we investigated the impact of integrating trimethyl chitosan (TMC) into a widely used poly(vinylpyrrolidone)-iodine gel (PVP-I gel). Our study assessed the antimicrobial efficacy of the PVP gel with TMC against Escherichia coli, Staphylococcus aureus, multidrug-resistant S. aureus MRSA, and Candida albicans. Additionally, we compared hemostatic effects using a liver puncture bleeding model and evaluated wound healing through histological sections from full-thickness dermal wounds in rats. The results indicate that incorporating TMC into the commercially available PVP-I gel did not compromise its antimicrobial activity. The incorporation of TMC into the PVP-I gel markedly improves its hemostatic activity. The regular application of the PVP-I gel with TMC resulted in an increased blood vessel count in the wound bed and facilitated the development of thicker fibrous tissue with a regenerated epidermal layer. These findings suggest that TMC contributes not only to antimicrobial activity but also to the intricate processes of tissue regeneration. In conclusion, incorporating TMC proves beneficial, making it a valuable additive to commercially available antiseptic agents.

Lysosomal Activation Mediated by Endocytosis in J774 Cell Culture Treated with N-Trimethyl Chitosan Nanoparticles.

Safety and effectiveness are the cornerstone objectives of nanomedicine in developing nanotherapies. It is crucial to understand the biological interactions between nanoparticles and immune cells. This study focuses on the manufacture by the microfluidic technique of N-trimethyl chitosan/protein nanocarriers and their interaction with J774 cells to elucidate the cellular processes involved in absorption and their impact on the immune system, mainly through endocytosis, activation of lysosomes and intracellular degradation. TEM of the manufactured nanoparticles showed spherical morphology with an average diameter ranging from 36 ± 16 nm to 179 ± 92 nm, depending on the concentration of the cargo protein (0, 12, 55 µg/mL). FTIR showed the crosslinking between N-trimethyl chitosan and the sodium tripolyphosphate and the α-helix binding loss of BSA. TGA revealed an increase in the thermal stability of N-trimethyl chitosan/protein nanoparticles compared with the powder. The encapsulation of the cargo protein used was demonstrated using XPS. Their potential to improve cell permeability and use as nanocarriers in future vaccine formulations was demonstrated. The toxicity of the nanoparticles in HaCaT and J774 cells was studied, as well as the importance of evaluating the differentiation status of J774 cells. Thus, possible endocytosis pathways and their impact on the immune response were discussed. This allowed us to conclude that N-trimethyl chitosan nanoparticles show potential as carriers for the immune system. Still, more studies are required to understand their effectiveness and possible use in therapies.

Immunological Assessment of Chitosan or Trimethyl Chitosan-Coated PLGA Nanospheres Containing Fusion Antigen as the Novel Vaccine Candidates Against Tuberculosis.

The crucial challenge in tuberculosis (TB) as a chronic infectious disease is to present a novel vaccine candidate that improves current vaccination and provides efficient protection in individuals. The present study aimed to evaluate the immune efficacy of multi-subunit vaccines containing chitosan (CHT)- or trimethyl chitosan (TMC)-coated PLGA nanospheres to stimulate cell-mediated and mucosal responses against Mycobacterium Tuberculosis (Mtb) in an animal model. The surface-modified PLGA nanoparticles (NPs) containing tri-fusion protein from three Mtb antigens were produced by the double emulsion technique. The subcutaneously or nasally administered PLGA vaccines in the absence or presence of BCG were assessed to compare the levels of mucosal IgA, IgG1, and IgG2a production as well as secretion of IFN-γ, IL-17, IL-4, and TGF-ß cytokines. According to the release profile, the tri-fusion encapsulated in modified PLGA NPs demonstrated a biphasic release profile including initial burst release on the first day and sustained release within 18 days. All designed PLGA vaccines induced a shift of Th1/Th2 balance toward Th1-dominant response. Although immunized mice through subcutaneous injection elicited higher cell-mediated responses relative to the nasal vaccination, the intranasally administered groups stimulated robust mucosal IgA immunity. The modified PLGA NPs using TMC cationic polymer were more efficient to elevate Th1 and mucosal responses in comparison with the CHT-coated PLGA nanospheres. Our findings highlighted that the tri-fusion loaded in TMC-PLGA NPs may represent an efficient prophylactic vaccine and can be considered as a novel candidate against TB.

Promising Antifungal Potential of Engineered Non-ionic Surfactant-Based Vesicles: In Vitro and In Vivo Studies.

Fungal keratitis (FK) is a corneal infection caused by different fungal species. It is treated by the topical application of natamycin (NAT). Nevertheless, this approach faces many limitations like toxic effects, frequent dosing, resistance, and patient discomfort. The present research reports the development of trimethyl chitosan (TMC) coated mucoadhesive cationic niosomes by a modified thin-film hydration method. TMC was synthesized using a one-step carbodiimide method and characterized by 1H-NMR and degree of quaternization (53.74 ± 1.06%). NAT, cholesterol (CHOL), span 60 (Sp60), and dicetyl phosphate (DCP) were used to prepare niosomes which were incubated with TMC to obtain mucoadhesive cationic NAT loaded niosomes (MCNNs). MCNNs showed a spherical shape with 1031.12 ± 14.18 nm size (PDI below 0.3) and 80.23 ± 5.28% entrapment efficiency. In vitro drug release studies showed gradual drug release from TMC coated niosomes as compared to the uncoated niosomes. MIC assay and disk diffusion assay revealed promising in vitro antifungal potential of MCNNs similar to the marketed formulation. For investigating in vivo performance, ocular retention and pharmacokinetics, ocular irritation, and ulcer healing studies were performed using the rabbit model. Mucoadhesive property and prolonged local drug release improved the safety and efficacy of NAT, suggesting that the developed niosomes could be an emerging system for effective treatment of fungal keratitis.

Coinhibition of S1PR1 and GP130 by siRNA-loaded alginate-conjugated trimethyl chitosan nanoparticles robustly blocks development of cancer cells.

There is an interconnected network between S1P/sphingosine-1-phosphate receptor 1 (S1PR1), IL-6/glycoprotein 130 (GP130), and signal transducer and activator of transcription 3 (STAT3) signaling pathways in the tumor microenvironment, which leads to cancer progression. S1P/S1PR1 and IL-6/GP130 signaling pathways phosphorylate and activate STAT3, and it then induces the expression of S1PR1 and interleukin-6 (IL-6) in a positive feedback loop leading to cancer progression. We hypothesized that blockade of this amplification loop can suppress the growth and development of cancer cells. Therefore, we silenced STAT3 upstream molecules including the S1PR1 and GP130 molecules in cancer cells using small interfering RNA (siRNA)-loaded alginate-conjugated trimethyl chitosan (ATMC) nanoparticles (NPs). The generated NPs had competent properties including the appropriate size, zeta potential, polydispersity index, morphology, high uptake of siRNA, high rate of capacity, high stability, and low toxicity. We evaluated the effects of siRNA loaded ATMC NPs on tumor hallmarks of three murine-derived cancer cell lines, including 4T1 (breast cancer), B16-F10 (melanoma), and CT26 (colon cancer). The results confirmed the tumor-suppressive effects of combinational targeting of S1PR1 and GP130. Moreover, combination therapy could potently suppress tumor growth as assessed by the chick chorioallantoic membrane assay. In this study, we targeted this positive feedback loop for the first time and applied this novel combination therapy, which provides a promising approach for cancer treatment. The development of a potent nanocarrier system with ATMC for this combination was also another aspect of this study, which should be further investigated in cancer animal models in further studies.

Codelivery of HIF-1α siRNA and Dinaciclib by Carboxylated Graphene Oxide-Trimethyl Chitosan-Hyaluronate Nanoparticles Significantly Suppresses Cancer Cell Progression.

PURPOSE: Hypoxia-inducible factor (HIF) is one of the critical components of the tumor microenvironment that is involved in tumor development. HIF-1α functionally and physically interacts with CDK1, 2, and 5 and stimulates the cell cycle progression and Cyclin-Dependent Kinase (CDK) expression. Therefore, hypoxic tumor microenvironment and CDK overexpression lead to increased cell cycle progression and tumor expansion. Therefore, we decided to suppress cancer cell expansion by blocking HIF-1α and CDK molecules. METHODS: In the present study, we used the carboxylated graphene oxide (CGO) conjugated with trimethyl chitosan (TMC) and hyaluronate (HA) nanoparticles (NPs) loaded with HIF-1α-siRNA and Dinaciclib, the CDK inhibitor, for silencing HIF-1α and blockade of CDKs in CD44-expressing cancer cells and evaluated the impact of combination therapy on proliferation, metastasis, apoptosis, and tumor growth. RESULTS: The results indicated that the manufactured NPs had conceivable physicochemical properties, high cellular uptake, and low toxicity. Moreover, combination therapy of cancer cells using CGO-TMC-HA NPs loaded with HIF-1α siRNA and Dinaciclib (SCH 727965) significantly suppressed the CDKs/HIF-1α and consequently, decreased the proliferation, migration, angiogenesis, and colony formation in tumor cells. CONCLUSIONS: These results indicate the ability of CGO-TMC-HA NPs for dual drug/gene delivery in cancer treatment. Furthermore, the simultaneous inhibition of CDKs/HIF-1α can be considered as a novel anti-cancer treatment strategy; however, further research is needed to confirm this treatment in vivo. Graphical Abstract The suppression of HIF-1α and CDKs inhibits cancer growth. HIF-1α is overexpressed by the cells present in the tumor microenvironment. The hypoxic environment elevates mitochondrial ROS production and increases p38 MAP kinase, JAK/STAT, ERK, JNK, and Akt/PI3K signaling, resulting in cyclin accumulation and aberrant cell cycle progression. Furthermore, the overexpression of HIF-1α/CDK results in increased expression of genes such as BCL2, Bcl-xl, Ki-67, TGFß, VEGF, FGF, MMP2, MMP9, and, HIF-1α and consequently raise the survival, proliferation, angiogenesis, metastasis, and invasion of tumor cells. In conclusion, HIF-1α-siRNA/Dinaciclib-loaded CGO-TMC-HA NPs can inhibit the tumor expansion by blockage of CDKs and HIF-1α (JAK: Janus kinase, STAT: Signal transducer and activator of transcription, MAPK: mitogen-activated protein kinase, ERK: extracellular signal-regulated kinase, JNK: c-Jun N-terminal kinase, PI3K: phosphatidylinositol 3-kinase).

A dual-adjuvanting strategy for peptide-based subunit vaccines against group A Streptococcus: Lipidation and polyelectrolyte complexes.

In order to improve the immunogenicity of peptide-based vaccines against group A Streptococcus (GAS), lipid moieties (C16 lipoamino acid and cholic acid) were conjugated with peptide antigen (P25-J8) and further modified with α-poly(glutamic acid) (α-PGA). Thus, positively charged lipopeptide vaccine candidates LCP-1 (P25-K(J8)-SS-C16-C16) and LCP-2 (P25-K(J8)-SS-K(cholic acid)) were synthesized. Negatively charged LCP-3 (P25-K(PGA-J8)-SS-K(cholic acid)) was also produced by attaching α-PGA to the J8 N-terminus of LCP-2. Polyelectrolyte complex (PEC) nanoparticles were formulated with heparin and/or trimethyl chitosan (TMC) for delivery of the lipopeptide vaccine candidates. The ability of the antigen-loaded nanoparticles to induce humoral immune responses was examined in outbred female Swiss mice following intranasal immunization. The antibodies produced were opsonic against all clinical GAS isolates tested.

Quaternary Ammonium Chitosans: The Importance of the Positive Fixed Charge of the Drug Delivery Systems.

As a natural polysaccharide, chitosan has good biocompatibility, biodegradability and biosecurity. The hydroxyl and amino groups present in its structure make it an extremely versatile and chemically modifiable material. In recent years, various synthetic strategies have been used to modify chitosan, mainly to solve the problem of its insolubility in neutral physiological fluids. Thus, derivatives with negative or positive fixed charge were synthesized and used to prepare innovative drug delivery systems. Positively charged conjugates showed improved properties compared to unmodified chitosan. In this review the main quaternary ammonium derivatives of chitosan will be considered, their preparation and their applications will be described to evaluate the impact of the positive fixed charge on the improvement of the properties of the drug delivery systems based on these polymers. Furthermore, the performances of the proposed systems resulting from in vitro and ex vivo experiments will be taken into consideration, with particular attention to cytotoxicity of systems, and their ability to promote drug absorption.

Carboxymethyl dextran-trimethyl chitosan coated superparamagnetic iron oxide nanoparticles: An effective siRNA delivery system for HIV-1 Nef.

Gene therapy, including small interfering RNA (siRNA) technology, is one of the leading strategies that help to improve the outcomes of the current therapeutic systems against HIV-1 infection. The successful therapeutic application of siRNAs requires their safe and efficient delivery to specific cells. Here, we introduce a superparamagnetic iron oxide nanoparticle (SPION) for delivering siRNA against HIV-1 nef (anti-nef siRNA) into two cell lines, HEK293 and macrophage RAW 264.7. SPIONs were coated with trimethyl chitosan (TMC), and thereafter, different concentrations of SPION-TMC were coated with different ratios of a carboxymethyl dextran (CMD) to modify the physicochemical properties and improve the biological properties of the nanocarriers. The nanoparticles exhibited a spherical shape with an average size of 112 nm. The obtained results showed that the designed delivery route enhanced the uptake of siRNA into both HEK293 and RAW 264.7 cells compared with control groups. Moreover, CMD-TMC-SPIONs containing anti-nef siRNA significantly reduced the expression of HIV-1 nef in HEK293 stable cells. The modified siRNA-loaded SPIONs also displayed no toxicity or apoptosis-inducing effects on the cells. The CMD-TMC-SPIONs are suggested as potential nanocarriers for siRNA delivery in gene therapy of HIV-1 infection.

Self-assembly of trimethyl chitosan and poly(anionic amino acid)-peptide antigen conjugate to produce a potent self-adjuvanting nanovaccine delivery system.

Short peptides derived from virulent pathogen proteins are promising antigens for the development of vaccines against infectious diseases. However, in order to mimic the danger signals associated with natural infection and stimulate an adaptive immune response, peptide antigens must be co-delivered with immune adjuvants. In this study, a group A streptococcus (GAS) M-protein derived B-cell epitope: J8, and universal T-helper epitope P25 containing peptides, were chemically coupled with different anionic amino acid-based polymers. The poly(anionic amino acid)-peptide antigen conjugates were mixed with trimethyl chitosan (TMC) to produce self-adjuvanting nanoparticulate vaccine candidates. TMC from two different sources were used to analyse their effect on immunogenicity. The nanoparticles produced from a peptide modified with 10 residues of polyglutamic acid and fungal TMC (NP5) stimulated production of the highest levels of serum antibodies in outbred mice. These antibodies were opsonic against all clinical GAS isolates tested.

Targeted thrombolysis by using c-RGD-modified N,N,N-Trimethyl Chitosan nanoparticles loaded with lumbrokinase.

Lumbrokinase (LK) has strong fibrinolytic and thrombolytic activities, but it has a short half-life, can be easily inactivated, and may cause hemorrhage as a side effect. This study develops a potential thrombolytic therapy by fabricating N,N,N-Trimethyl Chitosan (TMC) nanoparticles modified with the cyclic Arg-Gly-Asp-Phe-Lys peptide (c-RGD) and loaded with LK (i.e. c-RGD-LK-NPs). The binding of c-RGD to platelet membrane GPIIb/IIIa receptors is expected to enable targeted delivery of the c-RGD-conjugated TMC to the thrombus. The synthesized c-RGD-LK-NPs had a mean particle size of 232.0 nm, zeta potential of 19.8 mV, entrapment efficiency of 52.7% ± 2.5%, and loading efficiency of 17.4% ± 0.65%. Transmission electron microscopy showed that they were generally spherical. The c-RGD-LK-NPs gave a cumulative in vitro LK release of 80.6% over 8 h, and the activity of LK was close to 80%, indicating that the nanoparticles protected the activity of LK. In vitro blood clot lysis assays were carried out and in vivo thrombolysis effect was tested in Sprague-Dawley rats carotid artery thrombus model. In all cases, the c-RGD-LK-NPs showed superior performance compared with the free LK and the unmodified TMC nanoparticles loaded with LK. The c-RGD-LK-NPs reagent is expected to be potentially useful in treating thromboembolic diseases.

The Effect of Molecular Weight on the Antibacterial Activity of N,N,N-Trimethyl Chitosan (TMC).

N,N,N-trimethyl chitosan (TMC) with 93% degree of trimethylation was synthesized. TMC and the chitosan starting material were subjected to acidic hydrolysis to produce 49 different samples with a reduced average molecular weight (Mw) ranging from 2 to 144 kDa. This was done to allow the investigation of the relationship between antibacterial activity and Mw over a wide Mw range. NMR investigation showed that hydrolysis did not affect the degree of trimethylation (DSTRI) or the structure of the polymer backbone. The activity of TMC against Staphylococcus aureus (S. aureus) increased sharply with Mw until a certain Mw value (critical Mw for high activity, CMW) was reached. After the CMW, the activity was not affected by a further increase in the Mw. A similar pattern of activity was observed for chitosan. The CMW was determined to be 20 kDa for TMC and 50 kDa for chitosan.

Single-Step Methylation of Chitosan Using Dimethyl Carbonate as a Green Methylating Agent.

N,N,N-Trimethyl chitosan (TMC) is one chitosan derivative that, because of its improved solubility, has been studied for industrial and pharmaceutic applications. Conventional methods for the synthesis of TMC involve the use of highly toxic and harmful reagents, such as methyl iodide and dimethyl sulfate (DMS). Although the methylation of dimethylated chitosan to TMC by dimethyl carbonate (DMC, a green and benign methylating agent) was reported recently, it involved a formaldehyde-based procedure. In this paper we report the single-step synthesis of TMC from chitosan using DMC in an ionic liquid. The TMC synthesised was characterised by 1H NMR spectroscopy and a functionally meaningful degree of quaternisation of 9% was demonstrated after a 12-h reaction time.

Trimethyl Chitosan/Siloxane-Hybrid Coated Fe3O4 Nanoparticles for the Uptake of Sulfamethoxazole from Water.

The presence of several organic contaminants in the environment and aquatic compartments has been a matter of great concern in the recent years. To tackle this problem, new sustainable and cost-effective technologies are needed. Herein we describe magnetic biosorbents prepared from trimethyl chitosan (TMC), which is a quaternary chitosan scarcely studied for environmental applications. Core@shell particles comprising a core of magnetite (Fe3O4) coated with TMC/siloxane hybrid shells (Fe3O4@SiO2/SiTMC) were successfully prepared using a simple one-step coating procedure. Adsorption tests were conducted to investigate the potential of the coated particles for the magnetically assisted removal of the antibiotic sulfamethoxazole (SMX) from aqueous solutions. It was found that TMC-based particles provide higher SMX adsorption capacity than the counterparts prepared using pristine chitosan. Therefore, the type of chemical modification introduced in the chitosan type precursors used in the surface coatings has a dominant effect on the sorption efficiency of the respective final magnetic nanosorbents.

Responses of primary human nasal epithelial cells to EDIII-DENV stimulation: the first step to intranasal dengue vaccination.

BACKGROUND: About half of the world's population are living in the endemic area of dengue viruses implying that a rapid-mass vaccination may be required. In addition, a major target of dengue vaccine are children, thus, a needle-free administration is more attractive. These problems may be overcome by the alternative route of vaccination such as topical, oral and intranasal vaccination. Here, we investigated the possibility to deliver a dengue immunogen intranasally, a painless route of vaccination. The tested immunogen was the domain III of dengue serotype-3 E protein (EDIII-D3) loaded into trimethyl chitosan nanoparticles (EDIII-D3 TMC NPs). The primary human nasal epithelial cells, HNEpCs, were used as an in vitro model for nasal responses. RESULTS: At tested concentrations, EDIII-D3 TMC NPs not only exerted no detectable toxicity toward HNEpC cultures but also efficiently delivered EDIII-D3 immunogens into HNEpCs. Moreover, HNEpCs quickly and strongly produced proinflammatory cytokines (IL-1ß, IL-6, TNF-α), type-I IFN, the growth factors (GM-CSF, IL-7), the chemokines (MCP-1, MIP-1ß, IL-8), Th1-related cytokines (IL-2, IL-12p70, IL-17, IFN-γ) and Th2-related cytokine (IL-4) in response to EDIII-D3 TMC NPs treatment. CONCLUSIONS: A potential mucosal delivery system for dengue immunogens was revealed and found to stimulate a strong local innate antiviral response which possibly leading to a systemic adaptive immunity.

New trimethyl chitosan-based composite nanoparticles as promising antibacterial agents.

In the present study, densely dispersed silver nanoparticles (Ag NPs) were rapidly green synthesized in the presence of Rumex dentatus aqueous extract, followed by UV-irradiation reduction. The Ag NPs were characterized using UV-vis spectroscopy, FTIR, XRD, and TEM. Then, the Ag NPs were incorporated into interpenetrating polymeric networks based on cationic trimethyl chitosan (TMCS) and anionic poly(acrylamide-co-sodium acrylate) copolymer to develop a new series of composite nanoparticles as potential antibacterial agents. Both TMCS and poly(acrylamide-co-sodium acrylate) were prepared in the study, and characterized using FTIR, DSC, and SEM. The synthesized Ag NPs showed high purity and uniform particle size distribution with particle size ranged between 5 and 30 nm. The composite nanoparticles demonstrated homogeneous spherical shape with size in the range of 378-402 nm. Both Ag NPs and the composite nanoparticles showed promising bactericidal activity as compared with the control. Moreover, the antibacterial activity of the composite nanoparticles increased along with increasing the concentrations of Ag NPs and the TMCS.

New trimethyl chitosan-based composite nanoparticles as promising antibacterial agents.

In the present study, densely dispersed silver nanoparticles (Ag NPs) were rapidly green synthesized in the presence of Rumex dentatus aqueous extract, followed by UV-irradiation reduction. The Ag NPs were characterized using UV-vis spectroscopy, FTIR, XRD, and TEM. Then, the Ag NPs were incorporated into interpenetrating polymeric networks based on cationic trimethyl chitosan (TMCS) and anionic poly(acrylamide-co-sodium acrylate) copolymer to develop a new series of composite nanoparticles as potential antibacterial agents. Both TMCS and poly(acrylamide-co-sodium acrylate) were prepared in the study, and characterized using FTIR, DSC, and SEM. The synthesized Ag NPs showed high purity and uniform particle size distribution with particle size ranged between 5 and 30 nm. The composite nanoparticles demonstrated homogeneous spherical shape with size in the range of 378-402 nm. Both Ag NPs and the composite nanoparticles showed promising bactericidal activity as compared with the control. Moreover, the antibacterial activity of the composite nanoparticles increased along with increasing the concentrations of Ag NPs and the TMCS.

Ocular delivery of cyanidin-3-glycoside in liposomes and its prevention of selenite-induced oxidative stress.

CONTEXT: Cataracts have become the leading cause of blindness around the world, which is mainly mediated by oxidative stress. OBJECTIVE: N-trimethyl chitosan (TMC)-coated liposomes of cyanidin-3-glycoside (C3G) (C3G-TCL) were prepared to attenuate oxidative stress induced by selenite sodium in rats. MATERIALS AND METHODS: C3G-TCL were prepared by reverse-phase evaporation method and then coated with self-synthesized TMC. The physicochemical properties were determined. A gamma-scintigraphy study was employed to evaluate the precorneal elimination of the radioactive preparations. The transcorneal visualization for fluorescence-labeled samples was determined by confocal laser scanning microscopy (CLSM). The in vivo anti-oxidative study using C3G-TCL was carried out in rats with selenite-induced cataracts by topical administration. RESULTS: The sphere-like morphological characterization of the vesicles was confirmed by TEM, with a size of 158.3 ± 2.8 nm and a zeta potential of 31.7 mV. The encapsulation efficiency was (53.7 ± 0.2) % as measured by ultrafiltration. C3G-TCL showed a 3.3-fold increment in precorneal residence time when compared with that of the (99m)Tc-solution. A TMC coating enhanced the transepithelial transport of liposomes to a depth of 40-µm in the cornea. Moreover, C3G-TCL could significantly elevate the activity of superoxide dismutase and catalase in lens and also show a considerable reversal of reduced glutathione activity. The lipid peroxidation in lens was strongly prevented when compared with that of groups treated with uncoated C3G-loaded liposomes. DISCUSSION AND CONCLUSION: The coating material TMC for liposomes helps improve the anti-oxidative effect of C3G in vivo through prolonged residence time on the cornea and improved permeability in the corneal epithelium.

Development of chitosan-pullulan composite nanoparticles for nasal delivery of vaccines: optimisation and cellular studies.

Nasal immunisation with nanoparticles has already shown promising results. In this study, nanoparticle composites carrying BSA for nasal vaccination prepared using electrostatic interaction process between polycation N-trimethyl chitosan chloride (TMC), chitosan glutamate (CG), chitosan chloride (CCl) and polyanion carboxymethyl pullulan (CMP). A mass ratio of 2:1 for TMC-CMP combination produced stable nanocarriers. For CCl-CMP and CG-CMP formulations needed a mass ratio of 3:1. Loading efficiency was >90% for all formulations. Nanoparticles' size ranged from 207 to 603 nm. The surface charge of the complexes varied between +14 and +33 mV. SDS-PAGE integrity of the model antigen was also demonstrated. MTT studies showed that nanoparticle composites were less toxic to Calu-3 cells than the particles of cationic polymers alone. FITC-BSA loaded nanoparticles efficiently taken up by J774A.1 macrophages as confirmed by confocal microscopy highlighting the potential of these novel nanoparticulate carriers' use for nasal vaccination.