Preparation and Properties of 5-Fluorouracil-Loaded Chitosan Microspheres for the Intranasal Administration

Berberine hydrochloride-loaded dung beetle chitosan/sodium alginate microspheres ameliorate DSS-induced colitis and regulate gut microorganisms in mice

Berberine hydrochloride (BH) has long been known for its therapeutic efficacy. In the present study, we aimed to treat mice with colitis using dung beetle chitosan (DCS) -transported BH. To achieve this, BH-loaded DCS/sodium alginate microspheres (SA-DCS-BH) were prepared. The SA-DCS-BH was characterized using SEM, DLS, FT-IR, and XRD, then was used for administration and anti-inflammatory examination in mice. SEM and DLS confirmed the surface morphology of the microspheres, and the particle size was relatively uniform. FT-IR and XRD results confirmed that BH was successfully loaded. In vitro and in vivo studies showed that SA-DCS-BH had slow-release ability. After treatment with SA-DCS-BH, DAI was significantly reduced, colon weight and length increased, spleen length and weight reduced, concentrations of pro-inflammatory cytokines in colonic tissues were reduced, and gut microbiota species abundance was modulated. In addition, this study found a correlation between specific microbes and colitis indicators, Muribaculaceae showed sequential growth after receiving BH, SA-CS-BH, and SA-DCS-BH treatments, respectively. It was concluded that SA-DCS-BH effectively delivered the BH to the intestine with slow-release ability and exhibited anti-inflammatory effects by immune response. Compared to commercial chitosan, DCS has potential for modulating intestinal microorganisms and more suitable carrier for intestinal drug delivery systems.

Conventional Nanosized Drug Delivery Systems for Cancer Applications

Clinical responses and tolerability of conventional nanocarriers (NCs) are sometimes different from those expected in anticancer therapy. Thus, new smart drug delivery systems (DDSs) with stimuli-responsive properties and novel materials have been developed. Several clinical trials demonstrated that these DDSs have better clinical therapeutic efficacy in the treatment of many cancers than free drugs. Composition of DDSs and their surface properties increase the specific targeting of therapeutics versus cancer cells, without affecting healthy tissues, and thus limiting their toxicity versus unspecific tissues. Herein, an extensive revision of literature on NCs used as DDSs for cancer applications has been performed using the available bibliographic databases.

Formulation and Characterization of Losartan Loaded Chitosan Microspheres: Effect of Crosslinking Agents

OBJECTIVE

The present investigation entailed determination of effect of diverse cross-linking agents on Losartan Potassium loaded chitosan microspheres. The emulsion cross-linking method was employed to formulate the microspheres with an endeavour to achieve maximum sustained effect.

METHODS

The FTIR studies revealed absence of any interaction between Losartan and chitosan. The emulsion cross linking method was accomplished in three steps encompassing formation of an aqueous and oily phase, emulsification and cross-linking. A total of eighteen Losartan formulations were developed using six different cross-linkers at three varying level were screened for optimum parameters. The in vitro drug release parameters of optimum formulations (LC3, LE3, LF3, LG3, LS3 and LV3) containing citric acid, epichlorohydrin, formaldehyde, glutaraldehyde, suphuric acid and vanillin as cross-linkers were assessed to determine the sustained effect.

RESULTS

The values of evaluated parameters including percent yield (94.67%), average particle size (51.19 µm), drug content (44.38 mg) and entrapment efficiency (88.77%) connoted LG3 as the best formulation. Additionally, the values of relative measure of skewness (β₁=0.01 and γ₁=0.10) and platykurtic (β₂=1.26) size distribution were least for LG3 with spherical shape and smooth surface as revealed by SEM studies.

CONCLUSION

The outcome of in vitro release and other characterizations of microspheres explicitly revealed glutaraldehyde as the best cross-linker amongst the cross-linkers used herewith. The maximum sustained effect (lasting over a period of 24 h) accompanied with higher MDT and t_50% with lower%DE and Q_14h values thus corroborated the objective of attaining sustained release of Losartan.

Preparation of parenteral nanocrystal suspensions of etoposide from the excipient free dry state of the drug to enhance in vivo antitumoral properties

Nanoparticle technology in cancer chemotherapy is a promising approach to enhance active ingredient pharmacology and pharmacodynamics. Indeed, drug nanoparticles display various assets such as extended blood lifespan, high drug loading and reduced cytotoxicity leading to better drug compliance. In this context, organic nanocrystal suspensions for pharmaceutical use have been developed in the past ten years. Nanocrystals offer new possibilities by combining the nanoformulation features with the properties of solid dispersed therapeutic ingredients including (i) high loading of the active ingredient, (ii) its bioavailability improvement, and (iii) reduced drug systemic cytotoxicity. However, surprisingly, no antitumoral drug has been marketed as a nanocrystal suspension until now. Etoposide, which is largely used as an anti-cancerous agent against testicular, ovarian, small cell lung, colon and breast cancer in its liquid dosage form, has been selected to develop injectable nanocrystal suspensions designed to be transferred to the clinic. The aim of the present work is to provide optimized formulations for nanostructured etoposide solutions and validate by means of in vitro and in vivo evaluations the efficiency of this multiphase system. Indeed, the etoposide formulated as a nanosuspension by a bottom-up approach showed higher blood life span, reduced tumor growth and higher tolerance in a murine carcinoma cancer model. The results obtained are promising for future clinical evaluation of these etoposide nanosuspensions.

Chitosan/carbon quantum dot/aptamer complex as a potential anticancer drug delivery system towards the release of 5-fluorouracil

Nowadays, nanotechnology contributes diminishing side effects rather than traditional therapeutic methods like chemotherapy. Thus, designing a biocompatible specific targeted nanocarrier with prolonged half-life and enhanced bio-availability using simultaneous cell imaging seems urgent. To meet this demand, 5-fluorouracil-chitosan‑carbon quantum dot-aptamer (5-FU-CS-CQD-Apt) nanoparticle was successfully synthesized for specific targeted delivery of 5-FU anti-cancer drug used in breast cancer treatment and this was done by following facile water-in-oil (W/O) emulsification method. Physicochemical properties were characterized and high drug loading and entrapment efficiency were achieved. The average size and zeta potential of the nanoparticle were 122.7 nm and + 31.2 mV, respectively. According to the in-vitro drug release profile, 5-FU-CS-CQD-Apt released the drug in a controlled manner. MTT assay, flow cytometry, fluorescence microscopy, and gene expression results demonstrated that the blank nanoparticle was biocompatible, and 5-FU-CS-CQD-Apt could kill tumor cells efficiently. Bcl-2/Bax ratio was decreased after 5-FU-CS-CQD-Apt treatment in MCF-7 cells. It was concluded that 5-FU-CS-CQD-Apt could be used as a potential nanocarrier in breast cancer treatment.

Preclinical evaluation of local prolonged release of paclitaxel from gelatin microspheres for the prevention of recurrence of peritoneal carcinomatosis in advanced ovarian cancer

Patients with advanced ovarian cancer develop recurrence despite initial treatment response to standard treatment of surgery and intravenous/intraperitoneal (IP) chemotherapy, partly due to a limited peritoneal exposure time of chemotherapeutics. Paclitaxel-loaded genipin-crosslinked gelatin microspheres (PTX-GP-MS) are evaluated for the treatment of microscopic peritoneal carcinomatosis and prevention of recurrent disease. The highest drug load (39.2 µg PTX/mg MS) was obtained by immersion of GP-MS in aqueous PTX nanosuspension (PTXnano-GP-MS) instead of ethanolic PTX solution (PTXEtOH-GP-MS). PTX release from PTX-GP-MS was prolonged. PTXnano-GP-MS displayed a more controlled release compared to a biphasic release from PTXEtOH-GP-MS. Anticancer efficacy of IP PTX-GP-MS (PTXEtOH-GP-MS, D = 7.5 mg PTX/kg; PTXnano-GP-MS D = 7.5 and 35 mg PTX/kg), IP nanoparticular albumin-bound PTX (D = 35 mg PTX/kg) and controls (0.9% NaCl, blank GP-MS) was evaluated in a microscopic peritoneal carcinomatosis xenograft mouse model. PTXnano-GP-MS showed superior anticancer efficacy with significant increased survival time, decreased peritoneal carcinomatosis index score and ascites incidence. However, prolonged PTX release over 14 days from PTXnano-GP-MS caused drug-related toxicity in 27% of high-dosed PTXnano-GP-MS-treated mice. Dose simulations for PTXnano-GP-MS demonstrated an optimal survival without drug-induced toxicity in a range of 7.5-15 mg PTX/kg. Low-dosed PTXnano-GP-MS can be a promising IP drug delivery system to prevent recurrent ovarian cancer.