PEG4000 modified liposomes enhance the solubility of quercetin and improve the liposome functionality: in vitro characterization and the cellular efficacy

Fusion of polymer-coated liposomes and centrifugally spun microfibers as hybrid materials to enhance sustained release

Liposomes are employed for the delivery of molecular cargo in several classes of systems. For instance, the embedding of loaded liposomes in polymeric fibrous scaffolds has enabled the creation of hybrid materials that mimic biological membranes. Liposomes with unmodified surfaces have been predominantly integrated into fibers, which leads to instabilities due to interfacial incompatibility. In addition, electrospinning has been almost exclusively employed for fiber fabrication, which limits the potential for scale-up production. Here, we present the fabrication of hybrid biomimetic materials by fusing polymer-coated liposomes to force-spun microfibers to increase the stability of the hybrid materials and enhance the sustained release of the cargo. l-α-Phosphatidylcholine liposomes were coated with chitosan or polyethylene glycol (PEG). The nano-differential scanning calorimetry results confirm that polymer coating does not affect the phase transition temperature (T m) of the liposomes, where only the model drug, quercetin, reduced T m. Centrifugal spinning was employed to fabricate hydrophobic polycaprolactone (PCL) microfibers at various polymer concentrations and using various solvents and spinning parameters to increase the yield at the lowest fiber diameter. The highest microfiber production rate obtained occurred at a 20% (w/v) PCL concentration in 50 : 50 (v/v) chloroform and methanol solution with an average fiber diameter of 584.85 ± 26.30 nm. The non-chemical fusion of the polymer-coated liposomes and the fibrous scaffolds was promoted by immersion at T > T m, under ultrasonication. We hypothesize that the fusion is driven by hydrophobic interactions between the liposomes and the fibers, which merge the materials through the lipid bilayer. The fused hybrid material solved the burst release problem observed when adhering plain liposomes to nanofibers. Both PEG and chitosan yielded a sustained release, where the release rate with the former was faster. These results demonstrate that the fusion of polymer-coated liposomes and microfibers enables more effective blending of the loaded carriers into the polymer microfibers. Ultimately, the fused liposome/microfiber hybrids are stable matrices and enhance the sustained release of molecular cargo.

Optimization, characterization, and cytotoxicity studies of novel anti-tubercular agent-loaded liposomal vesicles

The treatment of tuberculosis is still a challenging process due to the widespread of pathogen strains resistant to antibacterial drugs, as well as the undesirable effects of anti-tuberculosis therapy. Hence, the development of safe and effective new anti-antitubercular agents, in addition to suitable nanocarrier systems, has become of utmost importance and necessity. Our research aims to develop liposomal vesicles that contain newly synthesized compounds with antimycobacterial action. The compound being studied is a derivative of imidazo-tetrazine named 3-(3,5-dimethylpyrazole-1-yl)-6-(isopropylthio) imidazo [1,2-b] [1,2,4,5] tetrazine compound. Several factors that affect liposomal characteristics were studied. The maximum encapsulation efficiency was 53.62 ± 0.09. The selected liposomal formulation T8* possessed a mean particle size of about 205.3 ± 3.94 nm with PDI 0.282, and zeta potential was + 36.37 ± 0.49 mv. The results of the in vitro release study indicated that the solubility of compound I was increased by its incorporation in liposomes. The free compound and liposomal preparation showed antimycobacterial activity against Mycobacterium tuberculosis H37Rv (ATCC 27294) at MIC value 0.94-1.88 μg/ml. We predict that the liposomes may be a good candidate for delivering new antitubercular drugs.

Application of advanced biomaterials in photothermal therapy for malignant bone tumors

Malignant bone tumors are characterized by severe disability rate, mortality rate, and heavy recurrence rate owing to the complex pathogenesis and insidious disease progression, which seriously affect the terminal quality of patients' lives. Photothermal therapy (PTT) has emerged as an attractive adjunctive treatment offering prominent hyperthermal therapeutic effects to enhance the effectiveness of surgical treatment and avoid recurrence. Simultaneously, various advanced biomaterials with photothermal capacity are currently created to address malignant bone tumors, performing distinctive biological functions, including nanomaterials, bioceramics (BC), polymers, and hydrogels et al. Furthermore, PTT-related combination therapeutic strategies can provide more significant curative benefits by reducing drug toxicity, improving tumor-killing efficiency, stimulating anti-cancer immunity, and improving immune sensitivity relative to monotherapy, even in complex tumor microenvironments (TME). This review summarizes the current advanced biomaterials applicable in PTT and relevant combination therapies on malignant bone tumors for the first time. The multiple choices of advanced biomaterials, treatment methods, and new prospects for future research in treating malignant bone tumors with PTT are generalized to provide guidance. Malignant bone tumors seriously affect the terminal quality of patients' lives. Photothermal therapy (PTT) has emerged as an attractive adjunctive treatment enhancing the effectiveness of surgical treatment and avoiding recurrence. In this review, advanced biomaterials applicable in the PTT of malignant bone tumors and their distinctive biological functions are comprehensively summarized for the first time. Simultaneously, multiple PTT-related combination therapeutic strategies are classified to optimize practical clinical issues, contributing to the selection of biomaterials, therapeutic alternatives, and research perspectives for the adjuvant treatment of malignant bone tumors with PTT in the future.

Phytochemicals and Cancer Treatment: Cell-Derived and Biomimetic Vesicles as Promising Carriers

The majority of anticancer agents currently used derive from natural sources: plants, frequently the ones employed in traditional medicines, are an abundant source of mono- and diterpenes, polyphenols, and alkaloids that exert antitumor activity through diverse mechanisms. Unfortunately, many of these molecules are affected by poor pharmacokinetics and limited specificity, shortcomings that may be overcome by incorporating them into nanovehicles. Cell-derived nanovesicles have recently risen to prominence, due to their biocompatibility, low immunogenicity and, above all, targeting properties. However, due to difficult scalability, the industrial production of biologically-derived vesicles and consequent application in clinics is difficult. As an efficient alternative, bioinspired vesicles deriving from the hybridization of cell-derived and artificial membranes have been conceived, revealing high flexibility and appropriate drug delivery ability. In this review, the most recent advances in the application of these vesicles to the targeted delivery of anticancer actives obtained from plants are presented, with specific focus on vehicle manufacture and characterization, and effectiveness evaluation performed through in vitro and in vivo assays. The emerging overall outlook appears promising in terms of efficient drug loading and selective targeting of tumor cells, suggesting further engrossing developments in the future.