A systematic study on chitosan-liposome based systems for biomedical applications

Multifunctional and stimuli-responsive liposomes in hepatocellular carcinoma diagnosis and therapy

Hepatocellular carcinoma (HCC) is the most prevalent type of liver cancer, mainly occurring in Asian countries with an increased incidence rate globally. Currently, several kinds of therapies have been deployed for HCC therapy including surgical resection, chemotherapy, radiotherapy and immunotherapy. However, this tumor is still incurable, requiring novel strategies for its treatment. The nanomedicine has provided the new insights regarding the treatment of cancer that liposomes as lipid-based nanoparticles, have been widely applied in cancer therapy due to their biocompaitiblity, high drug loading and ease of synthesis and modification. The current review evaluates the application of liposomes for the HCC therapy. The drugs and genes lack targeting ability into tumor tissues and cells. Therefore, loading drugs or genes on liposomes can increase their accumulation in tumor site for HCC suppression. Moreover, the stimuli-responsive liposomes including pH-, redox- and light-sensitive liposomes are able to deliver drug into tumor microenvironment to improve therapeutic index. Since a number of receptors upregulate on HCC cells, the functionalization of liposomes with lactoferrin and peptides can promote the targeting ability towards HCC cells. Moreover, phototherapy can be induced by liposomes through loading phtoosensitizers to stimulate photothermal- and photodynamic-driven ablation of HCC cells. Overall, the findings are in line with the fact that liposomes are promising nanocarriers for the treatment of HCC.

Chitosan-coated liposome with lysozyme-responsive properties for on-demand release of levofloxacin

As an anti-infection antibiotic delivery route, a drug-controlled release system based on a specific condition stimulus response can enhance drug stability and bioavailability, reduce antibiotic resistance, achieve on-demand release and improve targeting and utilization efficiency. In this study, chitosan-coated liposomes containing levofloxacin (Lef@Lip@CS) were prepared with lysozyme in body fluids serving as an intelligent "switch" to enable accurate delivery of antibiotics through the catalytic degradation ability of chitosan. Good liposome encapsulation efficacy (64.89 ± 1.86 %) and loading capacity (5.28 ± 0.18 %) were achieved. The controlled-release behavior and morphological characterization before and after enzymatic hydrolysis confirmed that the levofloxacin release rate depended on the lysozyme concentration and the degrees of deacetylation of chitosan. In vitro bacteriostatic experiments showed significant differences in the effects of Lef@Lip@CS before and after enzyme addition, with 6-h inhibition rate of 72.46 % and 100 %, and biofilm removal rates of 51 % and 71 %, respectively. These findings show that chitosan-coated liposomes are a feasible drug delivery system responsive to lysozyme stimulation.

Characterization of modified starch-based complexes-stabilized linolenic acid emulsions and their enhanced oxidative stability in vitro gastrointestinal digestion

A new approach of fabricating α-linolenic acid emulsions with enhanced oxidative stability in vitro digestion was established, using covalent octenyl succinic anhydride starch (OSAS)-soy protein (SP)-epigallocatechin-3-gallate (EGCG) complexes as emulsifiers. The physicochemical characteristics and surface morphology of emulsions were mainly characterized by rheological measurements, laser scanning microscope (CLSM) and cryo-scanning electron microscopy (Cryo-SEM). Results indicated that emulsions had dense interfacial layers and strong network structures. As a result, the stability and antioxidant ability of emulsions were improved significantly. In addition, the oxidative stability of emulsions in vitro gastrointestinal digestion was explored. Results showed that emulsions could maintain better oxidative stability owing to antioxidant activity of covalent OSAS-SP-EGCG complexes under gastrointestinal conditions. In particular, lipid hydroperoxide and malondialdehyde contents of emulsions prepared by 1:4 complexes were lower than 0.35 mmol/L and 20.5 nmol/mL, respectively, approximately half those of emulsions stabilized by OSAS (0.65 mmol/L and 39.5 nmol/mL). It was indicated that covalent OSAS-SP-EGCG complexes could effectively inhibit α-linolenic acid oxidation in emulsions during vitro gastrointestinal digestion. This work will provide a theoretical basis for the development of α-linolenic acid emulsions, which will help to broaden application of α-linolenic acid in food industry.

HAuCl4-mediated green synthesis of highly stable Au NPs from natural active polysaccharides: Synthetic mechanism and antioxidant property

Polysaccharide-functionalized gold nanoparticles (Polysaccharide-Au NPs) with high stability were successfully prepared by a straightforward method. Notably, the Au (III) ion acts as a strong Lewis acid to facilitate glycosidic bond breaking. Subsequently, the polysaccharide conformation was transformed to an open-chain form, exposing highly reduced aldehyde or ketone groups that reduce Au (III) to Au (0) crystal species, further growing into Au NPs. As-prepared Au NPs displayed excellent stability over a longer storage period (more than 70 days), a wide range of temperatures (25-60 °C), and pH range (3-11), varying concentrations (0-200 mM) and types of salt ions (Na+, K+, Ca2+, Mg2+), and glutathione solutions (5 mM). More interestingly, polysaccharide-Au NPs retained the antioxidant activity of polysaccharides and reduced oxidative damage at the cellular level through decreased reactive oxygen species (ROS) production. The intracellular levels of ROS pretreated with polysaccharide and polysaccharide-Au NPs were decreased 53.12-75.85 % compared to the H2O2 group, respectively. Therefore, the green synthesized Au NPs from natural active polysaccharides exhibit potential applications in biomedical fields.

Carboxymethyl chitosan and octadecylamine-coated liposome-containing WPTS: design, optimization, and evaluation

Liposomes (LPs) are a delivery system for stabilizing pharmaceuticals with limited use due to their propensity to congregate and fuse. A proposed method of addressing these problems is polymer coating. In this study, the potential of octadecylamine (ODA)-coated liposomes and carboxymethyl chitosan (CMCS/ODA-LPs) for enhancing Wacao pentacyclic triterpene saponin (WPTS) transport capacity was investigated. CMCS/ODA-LPs were produced by electrostatic adsorption and thin-film hydration. Response surface methodology (RSM) was employed to enhance the process and encapsulation efficiency (EE) for optimum drug encapsulation efficiency. The synthesized WPTS-CMCS/ODA-LPs were uniformly dispersed in a circular shape, and during 14 days of storage at 4 °C, the particle size and morphology did not significantly change. Vesicle size, zeta potential, polydispersity index (PDI), and entrapment efficiency (%) were 179.1 ± 7.31 nm, -29.6 ± 1.35 mV, 0.188 ± 0.052, and 75.62 ± 0.43, respectively. The hemolysis test revealed that WPTS-CMCS/ODA-LPs were sufficiently biocompatible. Compared to WPTS-LPs, WPTS-CMCS/ODA-LPs consistently showed a much more significant cytotoxic effect on cancer cells. Early and WPTS-CMCS/ODA-LPs-induced apoptosis resulted in almost seven times more cell death than the control. Compared to physiological pH 7.3, the pH-sensitive CMCS coupled LPs increased drug release at acidic pH 6.5. These findings suggest the efficacy of pH-sensitive CMCS/ODA-LPs as a medication delivery method for WPTS.

Chitosan-based Schiff bases: Promising materials for biomedical and industrial applications

There is plenty of scope for modifying chitosan, an only polycationic natural polysaccharide, owing to its reactive functional groups, namely hydroxyl and amino groups. Although innumerable numbers of chitosan derivatives have been synthesized by modifying these groups and reported elsewhere, in this review article, an attempt has been exclusively made to demonstrate the syntheses of various chitosan-based Schiff bases (CSBs) simply by allowing the reactions of reactive amino groups of chitosan with different aldehydes/ketones of interest. Due to their very peculiar and unique characteristics, such as biodegradability, biocompatibility, metal-binding capability, etc., they are found to be very useful for diversified applications. Thus, we have also attempted to showcase their very specific biomedical fields, including tissue engineering, drug delivery, and wound healing, to name a few. In addition, we have also discussed the utilization of CSBs for industrial applications such as wastewater treatment, catalysis, corrosion inhibition, sensors, etc.

Combining ZnPc-liposomes and chitosan on a hybrid matrix for enhanced photodynamic therapy

Photodynamic therapy is an alternative treatment for several pathologies, including cancer. This therapy uses a photosensitizer capable of producing reactive oxygen species through irradiation, promoting cellular death. A limitation of photosensitizers is their low solubility in aqueous media. Hence, developing a suitable carrier for photosensitizers for specific applications is a challenge. Cervical cancer is one of the most common cancers in women, and photodynamic therapy could be an attractive alternative therapeutic approach. In this work, we synthesized films composed of chitosan, polyvinylpyrrolidone, and liposomes containing Zn-phthalocyanine. Photophysical characterization of ZnPc incorporated into films was determined by UV-vis and fluorescence. Film properties such as swelling, mechanical properties, and water vapor permeability were performed. Finally, in vitro, photodynamic evaluation of these films was performed on HeLa cells. The results indicate that incorporating Zn-Pc-liposomes into films decreases cell viability by >95 %.

Advances in embedding techniques of anthocyanins: Improving stability, bioactivity and bioavailability

The health benefits of anthocyanins have attracted extensive research interest. However, anthocyanins are sensitive to certain environmental and gastrointestinal conditions and have low oral bioavailability. It has been reported that delivery systems made in different ways could improve the stability, bioavailability and bioactivity of anthocyanins. This present review summarizes the factors affecting the stability of anthocyanins and the reasons for poor bioavailability, and various technologies for encapsulation of anthocyanins including microcapsules, nanoemulsions, microemulsions, Pickering emulsions, nanoliposomes, nanoparticles, hydrogels and co-assembly with amphiphilic peptides were discussed. In particular, the effects of these encapsulation technologies on the stability, bioavailability and bioactivities of anthocyanins in vitro and in vivo experiments are reviewed in detail, which provided scientific insights for anthocyanins encapsulation methods. However, the application of anthocyanins in food industry as well as the biological fate and functional pathways in vivo still need to be further explored.

Influence of Auricularia cornea Polysaccharide Coating on the Stability and Antioxidant Activity of Liposomes Ginsenoside Rh2

Liposomes (Lip) are microstructures containing lipid and aqueous phases for encapsulation and delivery of bioactivators. In this study, Ginsenoside Rh2 liposomes (Rh2-Lip) were prepared by a thin-film hydrated ultrasonic binding method. But they are not stable during storage. In addition, Rh2-Lip was wrapped with Auricultural cornea polysaccharide (ACP) and Chitosan (CS) as coating materials to improve stability. CS coating was used as a positive control. The particle sizes determined by dynamic light scattering (DLS) showed 183 ± 5.52 nm for liposomes, 197 ± 6.7 nm for Auricultural cornea polysaccharide coated liposomes (ACP-Rh2-Lip), and 198 ± 3.5 nm for Chitosan coated liposomes (CS-Rh2-Lip). The polydispersity index (PDI) of all liposomes was less than 0.3. Transmission electron microscopy (TEM) showed that ACP and CS were successfully encapsulated on the liposome surface. In vitro simulations of digestive stability in the gastrointestinal tract showed that ACP-Rh2-Lip and CS-Rh2-Lip were more stable in gastrointestinal fluids compared to Lip. The antioxidant experiment revealed that ACP-Rh2-Lip has greater antioxidant activity than Lip. The purpose of this study was to look into the effects of ACP-Rh2-Lip and to offer a reference for Ginsenoside Rh2 (Rh2) delivery.

Specific surface modification of liposomes for gut targeting of food bioactive agents

Liposomes have become a research hotspot in recent years as food delivery systems with attractive properties, including the bilayer structure assembled like the cell membrane, reducing the side-effect and improving environmental stability of cargos, controlling release, extending duration of functional ingredients, and high biodegradable and biocompatible abilities in the body. However, the conventional liposomes lack stability during storage and are weak in targeted absorption in the gastrointestinal track. At present, surface modification has been approved to be an effective platform to shield these barricades and help liposomes deliver the agents safely and effectively to the ideal site. In this review, the gastrointestinal stability of conventional liposomes, cargo release models from liposomes, and the biological fate of the core materials after release were emphasized. Then, the strategies in both physical and chemical perspectives to improve the stability and utilization of liposomes in the gastrointestinal tract, and the emerging approaches for improving gut targeting by specifically modified liposomes and the intestinal receptors relative to liposomes/cargos absorption were highlighted. Last but not the least, the safety, challenges, and opportunities for the improvement of liposomal bioavailability were also discussed to inspire new applications of liposomes as oral carriers.

Drug delivery of extracellular vesicles: Preparation, delivery strategies and applications

Extracellular vesicles (EV) are cell-originated vesicles exhibited with characteristics similar to the parent cells. Several studies have suggested the therapeutic potential of EV since they played as an intercellular communicator and modulate disease microenvironment, and thus EV has been widely studied in cancer management and tissue regeneration. However, merely application of EV revealed limited therapeutic outcome in different disease scenario and co-administration of drugs may be necessary to exert proper therapeutic effect. The method of drug loading into EV and efficient delivery of the formulation is therefore important. In this review, the advantages of using EV as drug delivery system compared to traditional synthetic nanoparticles will be emphasized, followed by the method of preparing EV and drug loading. The pharmacokinetic characteristics of EV was discussed, together with the review of reported delivery strategies and related application of EV in different disease management.

Mucoadhesive Rifampicin-Liposomes for the Treatment of Pulmonary Infection by Mycobacterium abscessus: Chitosan or ε-Poly-L-Lysine Decoration

Mycobacterium abscessus (Mabs) is a dangerous non-tubercular mycobacterium responsible for severe pulmonary infections in immunologically vulnerable patients, due to its wide resistance to many different antibiotics which make its therapeutic management extremely difficult. Drug nanocarriers as liposomes may represent a promising delivery strategy against pulmonary Mabs infection, due to the possibility to be aerosolically administrated and to tune their properties in order to increase nebulization resistance and retainment of encapsulated drug. In fact, liposome surface can be modified by decoration with mucoadhesive polymers to enhance its stability, mucus penetration and prolong its residence time in the lung. The aim of this work is to employ Chitosan or ε-poly-L-lysine decoration for improving the properties of a novel liposomes composed by hydrogenated phosphatidyl-choline from soybean (HSPC) and anionic 1,2-Dipalmitoyl-sn-glycero-3-phosphorylglycerol sodium salt (DPPG) able to entrap Rifampicin. A deep physicochemical characterization of polymer-decorated liposomes shows that both polymers improve mucoadhesion without affecting liposome features and Rifampicin entrapment efficiency. Therapeutic activity on Mabs-infected macrophages demonstrates an effective antibacterial effect of ε-poly-L-lysine liposomes with respect to chitosan-decorated ones. Altogether, these results suggest a possible use of ε-PLL liposomes to improve antibiotic delivery in the lung.

Polysaccharide-modified liposomes and their application in cancer research

Nanodrug delivery systems have been widely used in cancer treatment. Among these, liposomal drug carriers have gained considerable attention due to their biocompatibility, biodegradability, and low toxicity. However, conventional liposomes have several shortcomings, such as poor stability, rapid clearance, aggregation, fusion, degradation, hydrolysis, and oxidation of phospholipids. Polysaccharides are natural polymers of biological origin that exhibit structural stability, excellent biocompatibility and biodegradability, flexibility, non-immunogenicity, low toxicity, and targetability. Therefore, they represent a promising class of polymers for the modification of the surface properties of liposomes to overcome their shortcomings. In addition, polysaccharides can be readily combined with other materials to develop new composite materials. Hence, they represent the optimal choice for liposomal modification to improve pharmacokinetics and clinical utility. Polysaccharide-coated liposomes exhibit better stability, drug release kinetics, and cellular uptake than conventional liposomes. The oncologic application of polysaccharide-coated liposomes has become a research hotspot. We summarize the preparation, physicochemical properties, and antineoplastic effects of polysaccharide-coated liposomes to facilitate antitumor drug development.

Carboxymethyl chitosan coated alpha-linolenic acid nanoliposomes: Preparation, stability and release in vitro and in vivo

Nanoliposome encapsulation combined with carboxymethyl chitosan (CMCS) surface decoration was employed to improve physicochemical stability and oral bioavailability of alpha-linolenic acid (ALA). Different nanoliposome systems including ALA-loaded nanoliposomes (ALA-NLs) and CMCS-coated ALA-NLs (CMCS-ALA-NLs) were characterized through dynamic light scattering, transmission electron microscope, Fourier transform infrared spectroscopy and differential scanning calorimetry. The results showed that CMCS-ALA-NLs had good encapsulation efficiency of 79% and layer formation with nanosized spherical carrier. The physicochemical stability of CMCS-ALA-NLs was better than that of ALA-NLs. CMCS-ALA-NLs were able to regulate the release of ALA in a simulated gastrointestinal environment. In vivo testing found that ALA concentration of CMCS-ALA-NLs had an area under the curve of 1.32, which was 1.28 times higher than that of ALA-NLs and 2 times higher than that of ALA-emulsion. The absorption of ALA was improved by CMCS-ALA-NLs. It suggested that CMCS-coated nanoliposomes should be an available delivery strategy for transporting ALA.

Liposome-trimethyl chitosan nanoparticles codeliver insulin and siVEGF to treat corneal alkali burns by inhibiting ferroptosis

Alkali burns are potentially blinding corneal injuries. Due to the lack of available effective therapies, the prognosis is poor. Thus, effective treatment methods for corneal alkali burns are urgently needed. Codelivery nanoparticles (NPs) with characteristics such as high bioavailability and few side effects have been considered effective therapeutic agents for ocular diseases. In this study, we designed a new combination therapy using liposomes and trimethyl chitosan (TMC) for the codelivery of insulin (INS) and vascular endothelial growth factor small interfering RNA (siVEGF) to treat alkali-burned corneas. We describe the preparation and characterization of siVEGF-TMC-INS-liposome (siVEGF-TIL), drug release characteristics, intraocular tracing, pharmacodynamics, and biosafety. We found that siVEGF-TIL could inhibit oxidative stress, inflammation, and the expression of VEGF in vitro and effectively maintained corneal transparency, accelerated epithelialization, and inhibited corneal neovascularization (CNV) in vivo. Morever, we found that the therapeutic mechanism of siVEGF-TIL is possibly relevant to the inhibition of the ferroptosis signaling pathway by metabolomic analysis. In general, siVEGF-TIL NPs could be a safe and effective therapy for corneal alkali burn.

Nanomaterials for Fluorescence and Multimodal Bioimaging

Bioconjugated nanomaterials replace molecular probes in bioanalysis and bioimaging in vitro and in vivo. Nanoparticles of silica, metals, semiconductors, polymers, and supramolecular systems, conjugated with contrast agents and drugs for image-guided (MRI, fluorescence, PET, Raman, SPECT, photodynamic, photothermal, and photoacoustic) therapy infiltrate into preclinical and clinical settings. Small bioactive molecules like peptides, proteins, or DNA conjugated to the surfaces of drugs or probes help us to interface them with cells and tissues. Nevertheless, the toxicity and pharmacokinetics of nanodrugs, nanoprobes, and their components become the clinical barriers, underscoring the significance of developing biocompatible next-generation drugs and contrast agents. This account provides state-of-the-art advancements in the preparation and biological applications of bioconjugated nanomaterials and their molecular, cell, and in vivo applications. It focuses on the preparation, bioimaging, and bioanalytical applications of monomodal and multimodal nanoprobes composed of quantum dots, quantum clusters, iron oxide nanoparticles, and a few rare earth metal ion complexes.

Laser thrombolysis and in vitro release kinetics of tPA encapsulated in chitosan polysulfate-coated nanoliposome

A major challenge in managing coronary artery disease is to find an effective thrombolytic therapy with minimal side effects. Laser thrombolysis is a practical procedure to remove the thrombus from inside blocked arteries, although it can cause embolism and re-occlusion of the vessel. The present study aimed to design a liposome drug delivery system for the controlled release of tissue plasminogen activator (tPA) and delivery of drug system into the thrombus by Nd:YAG laser at a wavelength of 532 nm for the treatment of arterial occlusive diseases. In this study, tPA encapsulated into the chitosan polysulfate-coated liposome (Lip/PSCS-tPA) was fabricated by a thin-film hydration technique. The particle size of Lip/tPA and Lip/PSCS-tPA was 88 and 100 nm, respectively. The release rate of tPA from Lip/PSCS-tPA was measured to be 35 % and 66 % after 24 h and 72 h, respectively. Thrombolysis through the delivery of Lip/PSCS-tPA into the thrombus during the laser irradiation was higher compared to irradiated thrombus without the nanoliposomes. The expression of IL-10 and TNF-α genes was studied by RT-PCR. The level of TNF-α for Lip/PSCS-tPA was lower than that of tPA, which can lead to improved cardiac function. Also, in this study, the thrombus dissolution process was studied using a rat model. After 4 h, the thrombus area in the femoral vein was significantly lower for groups treated with Lip/PSCS-tPA (5 %) compared to the groups treated with tPA alone (45 %). Thus, according to our results, the combination of Lip/PSCS-tPA and laser thrombolysis can be introduced as an appropriate technique for accelerating thrombolysis.

Deoxycholic acid-chitosan coated liposomes combined with in situ colonic gel enhances renal fibrosis therapy of emodin

BACKGROUND

Renal fibrosis is the final common pathological feature of various chronic kidney diseases (CKD). Despite recent advances, development of new treatments strategy is needed. Emodin (EMO), an important ingredient of Chinese medicine, rhubarb (Polygonaceae Rheum palmatum l.), has been reported to inhibit the development of renal fibrosis effectively. However, the poor oral bioavailability of EMO and the insufficient monotherapy therapy compromise its efficacy.

PURPOSE

In order to enhance renal fibrosis therapy of emodin, an innovative combination therapy based on deoxycholic acid-chitosan coated liposomes (DCS-Lips) and in situ colonic gel (IGE) was developed.

METHODS

For one, the DCS-Lips were prepared via electrostatic interaction by mixing anionic conventional Lips with cationic DCS, deoxycholic acid conjugated on the backbone of chitosan. The cellular uptake of FITC-labeled DCS-Lips in Caco-2 cell monolayer was evaluated by CLSM and flow cytometry, respectively. Permeability study was carried out using Caco-2 cell monolayer. For another, EMO-loaded in situ colonic gel (EMO-IGE) was prepared by mixing EMO nanosuspensions and plain in situ gel, which was obtained by the cold method. The EMO-IGE was assessed for morphology, gelation temperature, viscosity and in vitro drug release. Finally, the therapeutic efficacy of the combination strategy, oral DCS-Lips formulations and in situ colonic gel, was evaluated in unilateral ureteral obstruction (UUO) rat model. Additionally, 16S rDNA sequencing was performed on rats faces to investigate whether the combination strategy improves the microbial dysbiosis in UUO rats.

RESULTS

The prepared DCS-Lips produced small, uniformly sized nanoparticles, and significantly enhanced the cellular uptake and in vitro permeability of EMO compared to non-coated liposomes. Moreover, the EMO-IGE was characterized by short gelation time, optimal gelling temperature, and excellent viscosity. In UUO model, the combination of DCS-Lips (gavage) and IGE (enema) attenuated renal fibrosis effectively. The results of 16S rDNA sequencing illustrated that IGE could restore the gut microbial dysbiosis of UUO rats.

CONCLUSION

Overall, the combination of DCS-Lips and EMO-IGE alleviated renal fibrosis effectively, resulting from the improved oral bioavailability of EMO by DCS-Lips and the restoration of gut microbiota by EMO-IGE, thus, presenting an innovative and promising potential for renal fibrosis treatment.

Current Researches on Nanodrug Delivery Systems in Bladder Cancer Intravesical Chemotherapy

Bladder cancer is one of the most common malignant tumors in urinary system. Intravesical chemotherapy is a common adjuvant therapy after transurethral resection of bladder tumors. However, it has several disadvantages such as low drug penetration rate, short residence time, unsustainable action and inability to release slowly, thus new drug delivery and new modalities in delivery carriers need to be continuously explored. Nano-drug delivery system is a novel way in treatment for bladder cancer that can increase the absorption rate and prolong the duration of drug, as well as sustain the action by controlling drug release. Currently, nano-drug delivery carriers mainly included liposomes, polymers, and inorganic materials. In this paper, we reveal current researches in nano-drug delivery system in bladder cancer intravesical chemotherapy by describing the applications and defects of liposomes, polymers and inorganic material nanocarriers, and provide a basis for the improvement of intravesical chemotherapy drugs in bladder cancer.

NiII NPs entrapped within a matrix of l-glutamic acid cross-linked chitosan supported on magnetic carboxylic acid-functionalized multi-walled carbon nanotube: a new and efficient multi-task catalytic system for the green one-pot synthesis of diverse heterocyclic frameworks

In the present study, a new l-glutamic acid cross-linked chitosan supported on magnetic carboxylic acid-functionalized multi-walled carbon nanotube (Fe₃O₄/f-MWCNT-CS-Glu) nanocomposite was prepared through a convenient one-pot multi-component sequential strategy. Then, nickel^II nanoparticles (Ni^II NPs) were entrapped within a matrix of the mentioned nanocomposite. Afterward, the structure of the as-prepared Fe₃O₄/f-MWCNT-CS-Glu/Ni^II nanosystem was elucidated by various techniques, including FT-IR, PXRD, SEM, TEM, SEM-based EDX and elemental mapping, ICP-OES, TGA/DTA, and VSM. In the next part of this research, the catalytic applications of the mentioned nickel^II-containing magnetic nanocomposite were assessed upon green one-pot synthesis of diverse heterocyclic frameworks, including bis-coumarins (3a–n), 2-aryl(or heteroaryl)-2,3-dihydroquinazolin-4(1H)-ones (5a–r), 9-aryl-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-diones (7a–n), and 2-amino-4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles (9a–n). The good-to-excellent yields of the desired products, satisfactory reaction rates, use of water solvent or solvent-free reaction medium, acceptable turnover numbers (TONs) and turnover frequencies (TOFs), along with comfortable recoverability and satisfying reusability of the as-prepared nanocatalyst for at least eight successive runs, and also easy work-up and purification procedures are some of the advantages of the current synthetic protocols.

In this research work, an Fe₃O₄/f-MWCNT-CS-Glu/Ni^II hybrid nanocomposite was synthesized, characterized, and used as a new and efficient multi-task catalytic system for the green one-pot synthesis of diverse heterocyclic frameworks.

Targeting foodborne pathogens via surface-functionalized nano-antimicrobials

The incorporation of antibiotics and bioactive compounds into non-toxic nanoparticles has been popularly used to produce effective antimicrobial nanocarriers against foodborne pathogens. These systems can protect antimicrobials against harsh environments, control their release, and increase their antimicrobial activities; however, their functions can be decreased by some major barriers. Intracellular localization of bacteria protects them from the host immune system and antimicrobial agents. Also, bacteria can cause constant infection by nestling in professional phagocytic cells. In the last years, surface functionalization of nanocarriers by passive and active modification methods has been applied for their protection against clearance from the blood, increasing both circulation time and uptake by target cells. For achieving this objective, different functional agents such as specifically targeted peptides internalize ligands, saccharide ligands, or even therapeutic molecules (e.g., antibodies or enzymes) are used. In this review, techniques for functionalizing the surface of antimicrobial-loaded nanocarriers have been described. This article offers a comprehensive review of the potential of functional nanoparticles to increase the performance of antimicrobials against foodborne pathogens through targeting delivery.

Liposome Loaded Ion/Temperature Dual Responsive Gellan Gum Hydrogel as Potential Nasal-To-Brain Delivery System

Intranasal administration, which can bypass the blood-brain barrier (BBB), is widely recognized as a promising strategy for high-efficiency drug delivery to the brain. Herein, for the purpose of effectively delivering drugs to the brain via intranasal administration, glutathione (GSH)-modified gellan gum (GSH-GG) with ion/temperature dual responsive properties was synthesized and encapsulated on galanthamine hydrobromide (GH)-loaded liposomes (GH-Lipo) for effective GH delivery to the brain (GH-Lipo@GSH-GG). Our results demonstrated that GSH-GG greatly decreased the gelation temperature of GG from 44.0 °C to 22.1 °C without compromising its ion responsiveness. Moreover, GSH-GG had a good protection ability for GH-loaded liposomes without affecting its drug release. Most importantly, the finally obtained GH-Lipo@GSHGG showed acceptable targeted delivery of GH to the brain upon in vivo administration. Therefore, this formulation can be employed as a potential delivery system in nasal-to-brain delivery.

Advances in Nanoliposomes for the Diagnosis and Treatment of Liver Cancer

The mortality rate of liver cancer is gradually increasing worldwide due to the increasing risk factors such as fatty liver, diabetes, and alcoholic cirrhosis. The diagnostic methods of liver cancer include ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI), among others. The treatment of liver cancer includes surgical resection, transplantation, ablation, and chemoembolization; however, treatment still faces multiple challenges due to its insidious development, high rate of recurrence after surgical resection, and high failure rate of transplantation. The emergence of liposomes has provided new insights into the treatment of liver cancer. Due to their excellent carrier properties and maneuverability, liposomes can be used to perform a variety of functions such as aiding in imaging diagnoses, combinatorial therapies, and integrating disease diagnosis and treatment. In this paper, we further discuss such advantages.

Liposomal-Based Formulations: A Path from Basic Research to Temozolomide Delivery Inside Glioblastoma Tissue

Glioblastoma (GBM) is a lethal brain cancer with a very difficult therapeutic approach and ultimately frustrating results. Currently, therapeutic success is mainly limited by the high degree of genetic and phenotypic heterogeneity, the blood brain barrier (BBB), as well as increased drug resistance. Temozolomide (TMZ), a monofunctional alkylating agent, is the first line chemotherapeutic drug for GBM treatment. Yet, the therapeutic efficacy of TMZ suffers from its inability to cross the BBB and very short half-life (~2 h), which requires high doses of this drug for a proper therapeutic effect. Encapsulation in a (nano)carrier is a promising strategy to effectively improve the therapeutic effect of TMZ against GBM. Although research on liposomes as carriers for therapeutic agents is still at an early stage, their integration in GBM treatment has a great potential to advance understanding and treating this disease. In this review, we provide a critical discussion on the preparation methods and physico-chemical properties of liposomes, with a particular emphasis on TMZ-liposomal formulations targeting GBM developed within the last decade. Furthermore, an overview on liposome-based formulations applied to translational oncology and clinical trials formulations in GBM treatment is provided. We emphasize that despite many years of intense research, more careful investigations are still needed to solve the main issues related to the manufacture of reproducible liposomal TMZ formulations for guaranteed translation to the market.

Improved stability of liposome-stabilized emulsions as coencapsulation delivery system for vitamin B2, vitamin E and β-carotene

To realize the co-encapsulation of multiple nutraceuticals with different solubilities, Pickering emulsions stabilized by freshly-prepared liposome suspension stabilized emulsion (Fre-Lip-Sus-E) and hydrated lyophilized liposome stabilized emulsion (Hyd-Lyo-Lip-E) were prepared, in...

Application of Lipid-Based Nanocarriers for Antitubercular Drug Delivery: A Review

The antimicrobial drugs currently used for the management of tuberculosis (TB) exhibit poor bioavailability that necessitates prolonged treatment regimens and high dosing frequency to achieve optimal therapeutic outcomes. In addition, these agents cause severe adverse effects, as well as having detrimental interactions with other drugs used in the treatment of comorbid conditions such as HIV/AIDS. The challenges associated with the current TB regimens contribute to low levels of patient adherence and, consequently, the development of multidrug-resistant TB strains. This has led to the urgent need to develop newer drug delivery systems to improve the treatment of TB. Targeted drug delivery systems provide higher drug concentrations at the infection site, thus leading to reduced incidences of adverse effects. Lipid-based nanocarriers have proven to be effective in improving the solubility and bioavailability of antimicrobials whilst decreasing the incidence of adverse effects through targeted delivery. The potential application of lipid-based carriers such as liposomes, niosomes, solid lipid nanoparticles, nanostructured lipid carriers, nano and microemulsions, and self-emulsifying drug delivery systems for the treatment of TB is reviewed herein. The composition of the investigated lipid-based carriers, their characteristics, and their influence on bioavailability, toxicity, and sustained drug delivery are also discussed. Overall, lipid-based systems have shown great promise in anti-TB drug delivery applications. The summary of the reviewed data encourages future efforts to boost the translational development of lipid-based nanocarriers to improve TB therapy.

Carboxymethyl chitosan coated medium-chain fatty acid nanoliposomes: structure, composition, stability and in vitro release investigation

Medium-chain fatty acids (MCFAs) have been proven as an easy energy source and active ingredient to prevent obesity and other metabolic disorders. However, the inherent hydrophobic nature of MCFAs causes poor aqueous solubility and dissolution in the gastrointestinal (GI) tract, thus limiting their applications in aqueous foods. To address these issues, a nutraceutical carrier system was developed by coating nanoliposomes with carboxymethyl chitosan (CMCS) through a series of well-designed processes, including thin-film hydration, dynamic high pressure microfluidization (DHPM) and surface modification. Electron microscopy investigation reveals an obvious morphology evolution from the uncoated nanoliposomes (UC-LPs) to the final CMCS coated nanoliposomes (CMCS-LPs). Together with the FTIR results, it confirms the successful coating of CMCS. More importantly, the resultant CMCS-LPs have a more negatively charged surface with a ζ-potential value of around -18.5 mV, which helps to increase the stability by avoiding severe particle aggregation. Owing to the above benefits, the encapsulated MCFAs can be safely retained in a long storage period of 90 days at 4 °C and the new carrier system also exhibits a more sustained release of MCFAs in the GI fluid.

Preparation and characterisation of liposome loaded with chitosan-epigallocatechin gallate conjugate

Liposomes (LS) were prepared using chitosan-epigallocatechin gallate (CE) conjugate (0.1 and 0.5%, w/v) and soy phosphatidylcholine (SPC)/cholesterol as a lipid phase (LP) (30 and 60 µmol mL^-1). The encapsulation efficiency (EE), particle diameter, zeta potential, and polydispersity index of LS were observed. The highest EE (76.96%) was found when LS was prepared using 0.5% (w/v) of CE conjugate and 60 µmol mL^-1 of LP (CELP-60-0.5) (p < 0.05). FTIR analysis showed the interaction between choline present in SPC and OH-groups of CE conjugate. The phase transition temperature of CELP-60-0.5 was 134.67 °C, higher than other samples (p < 0.05). CELP-60-0.5 showed inhibitory action against Gram-positive and Gram-negative bacteria. Higher retention of antioxidant and antimicrobial activities of CELP-60-0.5 was observed than unencapsulated CE conjugate sample when stored for 28 days at 30 °C (p < 0.05). LS might be used as an efficient vesicle for maintaining bioactivities of CE conjugate, plausibly when used as a preservative in foods.

A comprehensive survey upon diverse and prolific applications of chitosan-based catalytic systems in one-pot multi-component synthesis of heterocyclic rings

Heterocyclic compounds are among the most prestigious and valuable chemical molecules with diverse and magnificent applications in various sciences. Due to the remarkable and numerous properties of the heterocyclic frameworks, the development of efficient and convenient synthetic methods for the preparation of such outstanding compounds is of great importance. Undoubtedly, catalysis has a conspicuous role in modern chemical synthesis and green chemistry. Therefore, when designing a chemical reaction, choosing and or preparing powerful and environmentally benign simple catalysts or complicated catalytic systems for an acceleration of the chemical reaction is a pivotal part of work for synthetic chemists. Chitosan, as a biocompatible and biodegradable pseudo-natural polysaccharide is one of the excellent choices for the preparation of suitable catalytic systems due to its unique properties. In this review paper, every effort has been made to cover all research articles in the field of one-pot synthesis of heterocyclic frameworks in the presence of chitosan-based catalytic systems, which were published roughly by the first quarter of 2020. It is hoped that this review paper can be a little help to synthetic scientists, methodologists, and catalyst designers, both on the laboratory and industrial scales.

Role of chitosan based nanomedicines in the treatment of chronic respiratory diseases

Chitosan-loaded nanomedicines provide a greater opportunity for the treatment of respiratory diseases. Natural biopolymer chitosan and its derivatives have a large number of proven pharmacological actions like antioxidant, wound healing, immuno-stimulant, hypocholesterolemic, antimicrobial, obesity treatment, anti-inflammatory, anticancer, bone tissue engineering, antifungal, regenerative medicine, anti-diabetic and mucosal adjuvant, etc. which attracted its use in the pharmaceutical industry. As compared to other polysaccharides, chitosan has excellent mucoadhesive characteristics, less viscous, easily modified into the chemical and biological molecule and gel-forming property due to which the drugs retain in the respiratory tract for a longer period of time providing enhanced therapeutic action of the drug. Chitosan-based nanomedicines would have the greatest effect when used to transport poor water soluble drugs, macromolecules like proteins, and peptides through the lungs. In this review, we highlight and discuss the role of chitosan and its nanomedicines in the treatment of chronic respiratory diseases such as pneumonia, asthma, COPD, lung cancer, tuberculosis, and COVID-19.

Chitosomes-In-Chitosan Hydrogel for Acute Skin Injuries: Prevention and Infection Control

Burns and other skin injuries are growing concerns as well as challenges in an era of antimicrobial resistance. Novel treatment options to improve the prevention and eradication of infectious skin biofilm-producing pathogens, while enhancing wound healing, are urgently needed for the timely treatment of infection-prone injuries. Treatment of acute skin injuries requires tailoring of formulation to assure both proper skin retention and the appropriate release of incorporated antimicrobials. The challenge remains to formulate antimicrobials with low water solubility, which often requires carriers as the primary vehicle, followed by a secondary skin-friendly vehicle. We focused on widely used chlorhexidine formulated in the chitosan-infused nanocarriers, chitosomes, incorporated into chitosan hydrogel for improved treatment of skin injuries. To prove our hypothesis, lipid nanocarriers and chitosan-comprising nanocarriers (≈250 nm) with membrane-active antimicrobial chlorhexidine were optimized and incorporated into chitosan hydrogel. The biological and antibacterial effects of both vesicles and a vesicles-in-hydrogel system were evaluated. The chitosomes-in-chitosan hydrogel formulation demonstrated promising physical properties and were proven safe. Additionally, the chitosan-based systems, both chitosomes and chitosan hydrogel, showed an improved antimicrobial effect against S. aureus and S. epidermidis compared to the formulations without chitosan. The novel formulation could serve as a foundation for infection prevention and bacterial eradication in acute wounds.

Fabrication and characterization of alginate-based films functionalized with nanostructured lipid carriers

This study focuses on the fabrication and characterization of alginate-based films functionalized by incorporating nanostructured lipid carriers (NLCs). The effect of different NLC/alginate mass ratios (R = 0.05, 0.1, 0.2, and 0.35) on the physical, morphological, mechanical, and barrier properties of the calcium-alginate films was evaluated. The addition of the NLCs significantly improved the UV-absorbing properties, without greatly altering their transparent appearance. As the NLC concentration increased, the tensile strength, elastic modulus, and swelling ratio of the films decreased, while their thermal stability, water vapor permeability, and contact angle increased. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) images of the films revealed that NLC incorporation led to a more porous internal structure and a rougher surface. Fourier Transform Infrared (FTIR) analysis indicated that there were no new interactions between the calcium-alginate and NLC constituents within the films. Overall, this study shows that NLCs can be successfully incorporated into calcium-alginate films and used to modulate their physicochemical properties. In future, it will be useful to examine the potential of these films to incorporate hydrophobic bioactives such as drugs, nutraceuticals, antimicrobials, antioxidants, and pigments for specific pharmaceutical or food applications.

Synthesis of 2,5-furandicarboxylic acid-enriched-chitosan for anti-inflammatory and metal ion uptake

The main aim of the present study is to synthesize a hitherto unreported polymer of chitosan (CS) and 2,5-furandicarboxylic acid (FDCA) derived from renewable biomass resources. For this purpose, CS was chosen which had -NH₂ groups as abundant active sites. Synthesis of 2,5-furandicarboxylic acid-enriched-chitosan polymer (CS-FDCA) was carried out by reaction involving EDC-NHS coupling reagents. The structure of CS-FDCA polymer was confirmed by various characterization techniques such as Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (¹H NMR), X-ray powder diffraction (XRD), high resolution-field emission scanning electron microscope (HR-FESEM), and thermogravimetric analysis (TGA). Moreover, CS and CS-FDCA were scrutinized to examine their efficacies towards ameliorate inflammation via detection of lipopolysaccharide (LPS) induced nitric oxide (NO) production. As compared to CS, CS-FDCA with low concentration (1.0 μM) exhibited the better efficacy to reduce the NO production. Furthermore, CS-FDCA polymer showed high as 12.6% of Cu²⁺ ion uptake while CS showed 9.2% of Cu²⁺ ion uptake. Overall, it can be inferred that CS-FDCA polymer is expected to be used for biomedical application and for the removal of metal contaminants from industrial wastewater.

Biopolymer-liposome hybrid systems for controlled delivery of bioactive compounds: Recent advances

Conventional liposomes still face many challenges associated with the poor physical and chemical stability, considerable loss of encapsulated cargo, lack of stimulus responsiveness, and rapid elimination from blood circulation. Integration of versatile functional biopolymers has emerged as an attractive strategy to overcome the limitation of usage of liposomes. This review comprehensively summarizes the most recent studies (2015-2020) and their challenges aiming at the exploration of biopolymer-liposome hybrid systems, including surface-modified liposomes, biopolymer-incorporated liposomes, guest-in-cyclodextrin-in-liposome, liposome-in-hydrogel, liposome-in-film, and liposome-in-nanofiber. The physicochemical principles and key technical information underlying the combined strategies for the fabrication of polymeric liposomes, the advantages and limitations of each of the systems, and the stabilization mechanisms are discussed through various case studies. Special emphasis is directed toward the synergistic efficiencies of biopolymers and phospholipid bilayers on encapsulation, protection, and controlled delivery of bioactives (e.g., vitamins, carotenoids, phenolics, peptides, and other health-related compounds) for the biomedical, pharmaceutical, cosmetic, and functional food applications. The major challenges, opportunities, and possible further developments for future studies are also highlighted.

The Formation of Chitosan-Coated Rhamnolipid Liposomes Containing Curcumin: Stability and In Vitro Digestion

There is growing interest in developing biomaterial-coated liposome delivery systems to improve the stability and bioavailability of curcumin, which is a hydrophobic nutraceutical claimed to have several health benefits. The curcumin-loaded rhamnolipid liposomes (Cur-RL-Lips) were fabricated from rhamnolipid and phospholipids, and then chitosan (CS) covered the surface of Cur-RL-Lips by electrostatic interaction to form CS-coated Cur-RL-Lips. The influence of CS concentration on the physical stability and digestion of the liposomes was investigated. The CS-coated Cur-RL-Lips with RL:CS = 1:1 have a relatively small size (412.9 nm) and positive charge (19.7 mV). The CS-coated Cur-RL-Lips remained stable from pH 2 to 5 at room temperature and can effectively slow the degradation of curcumin at 80 °C; however, they were highly unstable to salt addition. In addition, compared with Cur-RL-Lips, the bioavailability of curcumin in CS-coated Cur-RL-Lips was relatively high due to its high transformation in gastrointestinal tract. These results may facilitate the design of a more efficacious liposomal delivery system that enhances the stability and bioavailability of curcumin in nutraceutical-loaded functional foods and beverages.

Studies on non-gelatinous & thermo-responsive chitosan with the N-isopropylacrylamide by RAFT methodology for control release of levofloxacin

The non-gelatinous and thermo-responsive properties were introduced in chitosan by incorporating the chain of poly(N-isopropylacrylamide) via reversible addition-fragmentation chain transfer (RAFT) polymerization. To achieve this, the reaction was carried out at 80 °C by modifying the chitosan(CS) with RAFT agent as a macroinitiator (CS-RAFT), where the amine group of CS was protected with phthalic anhydride and then reacted with 4-cyano-4-[(dodecyl sulfanyl thiocarbonyl)sulfanyl]-pentanoic acid (CDSTSP) to form CS-RAFT agent. Further, the addition of NIPAAm chains onto CS-RAFT was carried out in N,N'-dimethylformamide (DMF) solvent by using 2,2'-azobisisobutyronitrile (AIBN) as an initiator in N₂ atmosphere. The controlled addition of NIPAAm chains on to CS was confirmed by ¹H NMR spectroscopy, further, a kinetic study was performed to get the characteristic features of the RAFT reaction. The product was characterized by ¹H NMR, FT-IR, UV-Visible spectroscopy, XRD, SEM, and TGA analyses. The product in aqueous solution showed LCST at 2.0 mg/mL on 33 ± 0.1 °C. Further, beads were prepared with the sodium alginate and loaded the water-soluble levofloxacin drug (60% w/w loading was achieved). The drug delivery process was studied in-vitro at 37 ± 0.1 °C & pH 7.4, which shown controlled release of drug up to 32 h and it was 71% of the loaded levofloxacin.

Extraction, Characterization and Incorporation of Hypericum scruglii Extract in Ad Hoc Formulated Phospholipid Vesicles Designed for the Treatment of Skin Diseases Connected with Oxidative Stress

An extract of Hypericum scruglii, an endangered endemic plant of Sardinia (Italy), was prepared and characterized. It was loaded in special phospholipid vesicles, glycerosomes, which were modified by adding maltodextrin (glucidex) and a polymer (gelatin or hyaluronan). The corresponding liposomes were also prepared and used as reference. The vesicles disclosed suitable physicochemical features for skin delivery. Indeed, their mean diameter ranged from 120 to 160 nm, they were homogeneously dispersed (polydispersity index ≤ 0.30), and their zeta potential was highly negative (~−45 mV). The vesicle dispersions maintained unchanged characteristics during 60 days of storage, were highly biocompatible, and were able to protect keratinocytes against damages due to oxidative stress induced by treating them with hydrogen peroxide. Vesicles were also capable of promoting cell proliferation and migration in vitro by means of a scratch wound assay. The results confirmed the fruitful delivery of the extract of H. scruglii in glycerosomes modified with glucidex and gelatin and their promising ability for skin protection and treatment.