Free Drug Solution Research Articles

Folate decorated lipid chitosan hybrid nanoparticles of 5-fluorouracil for enhanced anticancer efficacy against colon cancer

The study aimed to develop folate decorated lipid chitosan hybrid nanoparticles for targeted delivery of 5-fluorouracil in colon cancer by utilizing the overexpressed folate receptors on the surface of HT-29 and HCT 116 cancer cell lines. The developed formulations were prepared by the ionic gelation method with slight modifications. The developed formulations exhibited spherical morphology, smaller particle size (158 to 225 nm), zeta potential (32.24 to 35.95 mV), PDI (0.19 to 0.35), and high encapsulation efficiency (85.3 % to 94.2 %) with optimal physicochemical characteristics. The in vitro release showed a biphasic release pattern with an initial burst release followed by a sustained release for 48 h. Moreover, the in vitro cell line study revealed that FA-CLPN-2 exhibited an enhanced cellular uptake and greater cytotoxic effect in HT-29 and HCT 116 cell lines compared to non-targeted CLPN-2 and free drug solution due to the folate receptor facilitated endocytosis process. The in vivo toxicity study revealed the safety and biocompatibility of the developed formulations in biological systems. The stability study demonstrates the stability of the developed formulations. Overall, these results suggest that the folate decorated lipid chitosan hybrid nanoparticles could be used as a potential delivery system for tumor-targeted therapy with reduced side effects.

Radiolabeled Trastuzumab Solid Lipid Nanoparticles for Breast Cancer Cell: in Vitro and in Vivo Studies.

Radiolabeled trastuzumab (TRZ) loaded solid lipid nanoparticles (SLNs) were prepared by high shear homogenization and sonication techniques. The apoptosis mechanism of TRZ-SLNs was studied only with the MCF-7 cell line, while the cytotoxicity and cell binding capacity were investigated using breast cancer cells (MCF-7 and MDA-MB-231) and the human keratinocyte cell line (HaCaT). The particle sizes of TRZ-SLNs were found to be below 100 nm, and they possessed a negative charge. The high radiolabeling efficiency and good radiolabeling stability in saline and a cell culture medium were obtained in the results of radiolabeling studies. According to the in vitro studies, TRZ-SLNs were found to be biocompatible, and they effectively induced apoptosis in MCF-7 cells. After the parenteral injection of TRZ-SLNs into rats, a sustained release profile in blood circulation was achieved compared with free drug solution by the evaluation of pharmacokinetic parameters. As a conclusion, the study reveals that Technetium-99m (99mTc radiolabeled) TRZ loaded SLN formulations could be promising theranostic agents based on their characterization profiles, in vitro cellular uptake and apoptosis induction capacity, and in vivo pharmacokinetic profiles.

A cell-mimicking platelet-based drug delivery system as a potential carrier of dimethyl fumarate for multiple sclerosis

Dimethyl fumarate (DMF), is one of the lately approved therapeutic agents for the multiple sclerosis (MS) treatment. Despite the beneficial effects, DMF also suffers from low penetration into brain.In this study, we designed a precise drug delivery system of DMF to cross BBB for MS management. The novelty of this study is developing a cell based biomimetic vehicle for specific drug delivery to the inflamed area in peripheral and CNS. DMF-loaded platelet-based nanoparticle as a cell-based drug delivery system was developed and compared with chitosan nanogel and platelet membrane coated chitosan nanogel. Prepared nanoparticles were characterized for particle size, morphology, release characteristics, and drug loading parameters. In the optimum condition, all nanoparticles were prepared in desirable nano-size and showed appropriate loading parameters. The neuropharmacokinetic evaluation was performed by determining the brain uptake of DMF, and brain uptake clearance for passage from BBB. Results from in vivo study demonstrated that the brain concentration of nanoparticles was higher than the free drug solution. The brain uptake clearance and AUC (0-∞) brain of DMF-loaded platelet nanoparticle were higher than platelet membrane coated chitosan nanogel and chitosan nanogel. The results demonstrated that platelet nanoparticles can be proposed as a potential biomimetic carrier for MS management.

A different approach to immunochemotherapy for colon Cancer: Development of nanoplexes of cyclodextrins and Interleukin-2 loaded with 5-FU

Immune system deficiencies are crucial in the progression of cancer, predominantly because immune cells are not stimulated by cytokines to eradicate cancer cells. Immunochemotherapy is currently considered an innovative approach that creates pathways in cancer treatment, sometimes also aiding in the efficacy of chemotherapeutics. The aim of this study was to prepare a cyclodextrin (CD) nanoplex based on charge interaction to deliver the anticancer drug 5-fluorouracil (5-FU) and Interleukin-2 (IL-2), thereby forming a nanoscale drug delivery system aimed at chemo-immunotherapy for colorectal cancers. The CD:IL-2 nanoplexes were obtained with a particle size below 100 nm and a cationic surface charge based on the extent of charge interaction of the cationic CD polymer with negatively charged IL-2. The loading capacity of CD nanoplexes was 40% for 5-FU and 99.8% for IL-2. Nanoplexes maintained physical stability in terms of particle size and zeta potential in aqueous solution for 1 week at + 4 °C. Moreover, the structural integrity of IL-2 loaded into CD nanoplexes was confirmed by SDS-PAGE analysis. The cumulative release rates of both 5-FU and IL-2 were found to be more than 80% in simulated biological fluids in 12 h. Cell culture studies demonstrate that CD polymers are safe on healthy L929 mouse fibroblast cells. Drug-loaded CD nanoplexes were determined to have a higher anticancer effect than free drug solution against CT26 mouse colon carcinoma cells. In addition, intestinal permeability studies supported the conclusion that CD nanoplexes could be promising candidates for oral chemotherapy as well. In conclusion, effective cancer therapy utilizing the absorptive/cellular uptake effect of CDs, the synergic effect and co-transport of chemotherapeutic drugs and immunotherapeutic molecules is a promising approach. Furthermore, the transport of IL-2 with this nano-sized system can reduce or avoid its toxicity problem in the clinic.

DMPC/Chol liposomal copper CX5461 is therapeutically superior to a DSPC/Chol formulation

CX5461, a compound initially identified as an RNA polymerase inhibitor and more recently as a G-quadruplex binder, binds copper to form a complex. Our previous publication showed that the complexation reaction can be leveraged to formulate copper-CX5461 inside liposomes, improving the apparent solubility of CX5461 by over 500-fold and reducing the elimination of CX5461 from the plasma compartment following intravenous administration. In mouse models of acute myeloid leukemia, the resulting formulation was more effective than the free drug solution of CX5461 (pH 3.5) currently used in clinical trials. However, the gains observed with the liposomal formulation were minimal, despite significant increases in circulation half-life. Since the formulation technology used relied on liposomes and the fate of most compounds associated with liposomes is dependent on liposomal lipid composition, the studies described here were designed to evaluate how simple changes in lipid composition could affect therapeutic activity. The previously reported formulation method was simplified to ensure an easy scale-up process. In the modified method, pre-measured solid CX5461 was added to copper-containing liposomes prior to an incubation at 60 °C, which enabled copper-CX5461 complexation inside DSPC/Chol or DMPC/Chol liposomes. Efficacy was determined in BRCA-normal (BxPC3) and BRCA-deficient (Capan-1) models of pancreatic cancer. Both liposomal formulations enhanced the circulation lifetime of CX5461 compared to the free drug solution (pH 3.5). Unlike most compounds that are loaded using a transmembrane pH-gradient, the dissociation of CX5461 from liposomes prepared using the copper complexation method were comparable for DSPC/Chol and DMPC/Chol liposomes, in vitro and in vivo. Nonetheless, copper CX5461 prepared using DMPC/Chol liposomes exhibited superior efficacy. The reason for the improved activity of DMPC/Chol copper-CX5461 was not readily explained by the release data and may be due to the fact that DMPC/Chol liposomes are less stable following localization in the tumor. The results indicate that the therapeutic effects of copper-CX5461 will be dependent on liposomal lipid composition and that liposomal CX5461 should exhibit superior benefits when used to treat BRCA-deficient cancers.

Enhanced Antibacterial Activity of Doxycycline and Rifampicin Combination Loaded in Nanoparticles against Intracellular Brucella abortus

Brucellosis is a zoonotic disease that is prevalent in livestock animals. The bacteria reside inside the macrophage cells of the host. The WHO has endorseda combination treatment therapy for brucellosis against the conventional monotherapy to avoid relapse and resistance. Therefore, we developed nanoparticles incorporating doxycycline and rifampicin in combination. The aim of the study is to develop polymeric nanoparticles incorporating doxycycline as well as rifampicin and investigate the antibacterial activity of nanoparticles in U937 human macrophage cells infected with B. abortus. Polymeric nanoparticles were developed by the emulsion-solvent diffusion method, and characterization was performed. The nanoparticles with high entrapment efficiency of both the drugs were developed successfully. Scanning electron microscopy revealed a spherical morphology with a size ranging ~450nm, which can be easily engulfed by the macrophages. Zeta potential confirmed the colloidal stability. Differential scanning calorimetry and X-ray diffraction suggested amorphization of doxycycline and rifampicin in nanoparticles. Fourier transfer infrared spectroscopy could not confirm the interaction of drugs with AOT. In vitro haemolysis study confirmed the safety of nanoparticles (<10%) for IV administration. Further, nanoparticles revealed the sustained release of both drugs, which followed diffusion kinetics. Nanoparticles were found stable for 6 months as per WHO guidelines. The internalization study revealed nanoparticles could be easily uptaken by U-937 human macrophage cells. The efficacy study demonstrated significantly high antibacterial activity of nanoparticles as compared to free drug solution in U937 human macrophages cells infected with Brucella abortus. It can be concluded that the developed nanoparticles entrapping doxycycline and rifampicin combination can be considered as a promising delivery system for enhancing the antibacterial activity against Brucella abortus.

Cell-penetrating peptide-surface modified liposomes to enhance the intestinal absorption of enoxaparin

Enoxaparin is low-molecular-weight heparin administered by subcutaneous/intravenous injection. The oral bioavailability of enoxaparin is restricted by its low absorption through the intestine. In this study cell-penetrating peptide-surface functionalized liposomes (CPPs-L) were prepared to improve the intestinal absorption of enoxaparin. Liposomal formulations were prepared by the ethanol injection method and the intestinal absorption of the formulation was evaluated using single-pass intestinal perfusion (SPIP) technique in rats. Meanwhile, the human fraction dose absorbed value (Fa (human)) of the formulations were predicted based on the calculated effective intestinal permeability (P effect (rat)) values obtained from the SPIP study. Liposomal enoxaparin revealed an increased intestinal absorption by ten-time compared with the free drug solution. Meanwhile, CPPs-L formulation revealed an enhanced intestinal absorption compared with the un-modified liposomal formulation. Regarding Fa (human), it is predicted that liposomal formulations could have the potential to improve the fraction dose absorbed of enoxaparin from low to intermediate level. Overall, the liposomal formulation can be considered as a mighty drug carrier for the oral delivery of enoxaparin.

Host-guest inclusion systems of two bioactive natural products derivantives and three polyamine-modified β-cyclodextrins: Preparation, characterization, biological activity

Two bioactive natural products derivatives including hydroxycamptothecin (HCPT) and etoposide (EPEG), which are one of the most common classes of first-line anticancer drugs used for the treatment of cancer. Of note, their application is still limited by poor water solubility and bioavailability. Therefore, it is very important to develop a new means to solve these shortcomings. In this work, the molecular binding behavior of three polyamine-modified β-cyclodextrins (H1-3) with HCPT and EPEG was investigated. The six novel H1-3/HCPT (EPEG) inclusion complexes were prepared and characterized by Fourier transform infrared spectrometry (FTIR), 2D nuclear magnetic resonance (2D ROESY), 1H nuclear magnetic resonance (NMR), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The phase solubility diagrams indicated that the stability constants (K1:1) of host H1-3 to the free drugs decrease sequentially as follows: H3>H2>H1. After forming inclusion complexes with H1-3, the water solubility of HCPT (EPEG) were obviously increased from the initial value of 0.0011 mg/mL (0.373 mg/mL) to 0.90 mg/mL (32.55 mg/mL), 2.01 mg/mL (38.73 mg/mL), and 2.39 mg/mL (47.42 mg/mL), enhanced by 84.9–225.5 times compared with the free drug, respectively. The in vitro release tests confirmed that the cumulative release of drug from H1-3/EPEG (HCPT) complexes was significantly higher than that from free drug solution in 50 h. The cytotoxicity assay showed that the H1/HCPT exhibited higher cytotoxicity towards MCF-7 cell in comparison to the free drug HCPT. Meanwhile, the toxicity of HCPT is obviously reduced after the formation of H2/HCPT. Apoptosis experiments revealed that the percentage of apoptotic cells was increased by H3/HCPT (65.80%), which close to increasing by free drugs HCPT (74.00%) when the concentrations of H3/HCPT and HCPT reached to a certain level (5.0 μg/mL). The satisfactory water solubility, high activity, and low toxicity of H1-3/HCPT (EPEG) inclusion complexes contributes to research with new applications of the HCPT and EPEG as anticancer drug formulations.

Hyaluronan-Cholesterol Nanogels for the Enhancement of the Ocular Delivery of Therapeutics.

The anatomy and physiology of the eye strongly limit the bioavailability of locally administered drugs. The entrapment of therapeutics into nanocarriers represents an effective strategy for the topical treatment of several ocular disorders, as they may protect the embedded molecules, enabling drug residence on the ocular surface and/or its penetration into different ocular compartments. The present work shows the activity of hyaluronan-cholesterol nanogels (NHs) as ocular permeation enhancers. Thanks to their bioadhesive properties, NHs firmly interact with the superficial corneal epithelium, without penetrating the stroma, thus modifying the transcorneal penetration of loaded therapeutics. Ex vivo transcorneal permeation experiments show that the permeation of hydrophilic drugs (i.e., tobramycin and diclofenac sodium salt), loaded in NHs, is significantly enhanced when compared to the free drug solutions. On the other side, the permeation of hydrophobic drugs (i.e., dexamethasone and piroxicam) is strongly dependent on the water solubility of the entrapped molecules. The obtained results suggest that NHs formulations can improve the ocular bioavailability of the instilled drugs by increasing their preocular retention time (hydrophobic drugs) or facilitating their permeation (hydrophilic drugs), thus opening the route for the application of HA-based NHs in the treatment of both anterior and posterior eye segment diseases.

Optimization and Development of Selective Histone Deacetylase Inhibitor (MPT0B291)-Loaded Albumin Nanoparticles for Anticancer Therapy.

Histone deacetylase (HDAC) inhibitors have emerged as a new class of antitumor agent for various types of tumors. MPT0B291, a novel selective inhibitor of HDAC6, demonstrated significant antiproliferative activity in various human cancer cell types. However, MPT0B291 has very low water solubility, which limits its clinical use for cancer therapy. In the current study, MPT0B291 was encapsulated in human serum albumin (HSA), and its anticancer activities were investigated. Nanoparticles (NPs) were prepared using two-stage emulsification resulting in 100~200-nm NPs with a fine size distribution (polydispersity index of <0.3). The in vitro drug release profiles of MPT0B291-loaded HSA NPs presented sustained-release properties. The cytotoxic effect on MIA PaCa-2 human pancreatic carcinoma cells was found to be similar to MPT0B291-loaded HSA NPs and the free-drug group. The albumin-based formulation provided a higher maximum tolerated dose than that of a drug solution with reduced toxicity toward normal cells. Furthermore, in vivo pharmacokinetic studies demonstrated an effective increase (5~8-fold) in the bioavailability of NPs containing MPT0B291 loaded in HSA compared to the free-drug solution with an extended circulation time (t1/2) leading to significantly enhanced efficacy of anticancer treatment.

Preparation of Carbopol 934 Based Ketorolac Tromethamine Buccal Mucoadhesive Film: In Vitro, Ex Vivo, and In Vivo Assessments

The goal of present investigation was to formulate and evaluate ketorolac tromethamine (KTM) mucoadhesive buccal films. The films were prepared by solvent evaporation method using PVP K30, HPMC K4M, HPMC K15M, carbopol 934, chitosan, and sodium alginate as polymers and propylene glycol as plasticizer. The films were evaluated for thickness, weight variation, folding endurance, surface pH, swelling index, in vitro residence time, in vitro diffusion, release kinetics, ex vivo permeation, in vitro-ex vivo correlation, and in vivo pharmacological activities such as anti-inflammatory and analgesic activity. Thickness, weight, drug content, and folding endurance were found to be uniform for the films. Surface pH was 6.85 ± 0.10 , and swelling index was the highest ( 27.27 ± 0.37 ) for the best film containing carbopol 934 along with sodium alginate and PVP K 30 (formulation code F2). In vitro residence time was greater than 5 h, and in vitro % drug release was 98.71% for F2. It exhibited 55.49% of swelling inhibition at 5 h, and above 38.88% was maintained at even 8 h. The film F2 has shown maximum analgesic response of 17 sec at 5 h, and the response of 11 sec was maintained at even 8 h. The anti-inflammatory and analgesic effect of F2 was found be maximum while sustaining the effect for prolonged period when compared to free drug solution. Thus, KTM mucoadhesive buccal film containing carbopol 934, sodium alginate, and PVP K30 could be an effective alternative for conventional therapy with improved efficacy.

Primaquine Loaded Solid Lipid Nanoparticles (SLN), Nanostructured Lipid Carriers (NLC), and Nanoemulsion (NE): Effect of Lipid Matrix and Surfactant on Drug Entrapment, in vitro Release, and ex vivo Hemolysis.

Primaquine (PQ), an 8-aminoquinoline antimalarial drug, has been widely used for the eradication of hypnozoites from the liver and, therefore, recognized as the radical cure of malaria. However, the clinical applications of PQ are restricted to patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to severe dose-related hemolytic side effects. Nanoparticle carriers have shown great potential in achieving higher PQ concentrations in the target site, thereby reducing dose-related systemic toxicity caused by non-specific exposure. This work aims to develop, compare, and evaluate three PQ-loaded lipid-based drug carriers including solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC), and nano-emulsions (NE). The optimized PQ-SLN, PQ-NLC, and PQ-NE had a particle size of 250nm, a PDI range of 0.1 to 0.3, a zeta potential of - 30mV, and entrapment efficiency of ~ 90%. All lipid formulations showed sustained release in both simulated gastric and intestinal fluids over 6h. Four empirical models - including zero-order, Higuchi, Korsmeyer-Peppas, and Hixson-Crowell models - were tested to understand the drug release mechanisms of PQ-SLN, PQ-NLC, and PQ-NE. The model fitness was found to be the highest in the Korsmeyer-Peppas model for all the PQ-loaded lipid formulations (R2: 0.88-0.94). No significant changes were observed in the entrapment efficiency, particle size, and PDI of lipid formulations throughout 1month of storage at 4°C and 25°C. PQ-SLN and PQ-NLC can be further lyophilized with cryoprotectants to improve long-term stability. Finally, the treatment of erythrocytes with PQ-SLN, PQ-NLC, and PQ-NE reduced erythrocyte hemolysis by approximately 4.5-fold compared to the free drug solution.

Biomimetic, ROS-detonable nanoclusters — A multimodal nanoplatform for anti-restenotic therapy

The long-term success of endovascular intervention has long been overshadowed by vessel re-occlusion, also known as restenosis. Mainstream anti-restenotic devices, such as drug-eluting stent (DES) and drug-coated balloon (DCB), were recently shown with suboptimal performances and life-threatening complications, thereby underpinning the urgent need for alternative strategies with enhanced efficacy and safety profile. In our current study, we engineered a multimodal nanocluster formed by self-assembly of unimolecular nanoparticles and surface coated with platelet membrane, specifically tailored for precision drug delivery in endovascular applications. More specifically, it incorporates the combined merits of platelet membrane coating (lesion targetability and biocompatibility), reactive oxygen species (ROS)-detonable “cluster-bomb” chemistry (to trigger the large-to-small size transition at the target site, thereby achieving longer circulation time and higher tissue penetration), and sustained drug release. Using RVX-208 (an emerging anti-restenotic drug under clinical trials) as the model payload, we demonstrated the superior performances of our nanocluster over conventional poly(lactic-co-glycolic acid) (PLGA) nanoparticle. In cultured vascular smooth muscle cell (VSMC), the drug-loaded nanocluster induced effective inhibition of proliferation and protective gene expression (e.g., APOA-I) with a significantly reduced dosage of RVX-208 (1 μM). In a rat model of balloon angioplasty, intravenous injection of Cy5.5-tagged nanocluster led to greater lesion targetability, improved biodistribution, and deeper penetration into injured vessel walls featuring enriched ROS. Moreover, in contrast to either free drug solution or drug-loaded PLGA nanoparticle formulation, a single injection with the drug-loaded nanocluster (10 mg/kg of RVX-208) was sufficient to substantially mitigate restenosis. Additionally, this nanocluster also demonstrated biocompatibility according to in vitro cytotoxicity assay and in vivo histological and tissue qPCR analysis. Overall, our multimodal nanocluster offers improved targetability, tissue penetration, and ROS-responsive release over conventional nanoparticles, therefore making it a highly promising platform for development of next-generation endovascular therapies.

Co-delivery of Pirarubicin and Vinorelbine by Micelles for the Treatment of Breast Cancer

To develop a pirarubicin (THP) and vinorelbine (VRL) codelivery nano-micellar system (T+V-CS micelles) of pirarubicin (THP) and vinorelbine (VRL) by using chondroitin sulfate-cholesterol polymers (CS-Chol) and DSPE-mPEG 2000 and to evaluate the therapeutic efficacy of the codelivery nano-micelles in breast cancer treatment. T+V-CS micelles were prepared by ultrasonic-dialysis method, and the physicochemical characterization were evaluated using multiple technological means. The anti-tumor efficacy of T+V-CS micelles in vitro was evaluated by MTT assay and cell cycle arrest analysis. Evaluation of the therapeutic effect of T+V-CS micelles in vivo was carried out on xenograft 4T1 murine breast cancer bearing BALB/c mice model. T+V-CS micelles displayed a nearly spherical shape when observed through transmission electron microscope. The particle size and polydispersity indexes (PDI) of T+V-CS micelles was (155.5±4.5) nm and 0.170±0.003 respectively, while the Zeta potential was (-23.0±0.9) mV. Meanwhile, T+V-CS micelles demonstrated high encapsulation efficiency of (81.87±2.56)% for THP and (87.54±2.82)% for VRL and a high overall drug loading efficiency of (10.20±1.20)%. In vitro and in vivo studies of the therapeutic efficacy of breast cancer showed that T+V-CS micelles had synergistic anti-tumor effect and induced increased G 2/M cell cycle arrest in 4T1 cells, which could significantly inhibit tumor growth and prolong survival compared with the therapeutic efficacy of micelles loaded with a single kind of drug or free drug solutions. The study showed that T+V-CS micelles had excellent anti-tumor effect, offering a reference to the clinical treatment of breast cancer.

Design, development and in-vitro/in-vivo evaluation of intranasally delivered Rivastigmine and N-Acetyl Cysteine loaded bifunctional niosomes for applications in combinative treatment of Alzheimer’s disease

The present investigation explores the potential of novel dual drug-loaded niosomes for nasal delivery of Rivastigmine (RIV) and N-Acetyl Cysteine (NAC) to the brain. The dual niosomes showed a particle size of 162.4 nm and % entrapment efficiencies of 97.7% for RIV and 85.9% for NAC. The niosomes were statistically validated using Box-Behnken experimental design (BBD) with good significance. Ultrastructural and chemical characterization of the niosomes using various analytical techniques like Fourier Transform Infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Transmission electron microscopy (TEM) showcased drug-excipient compatibility and robust stability of 6 months in a liquid state at 4–8 °C. The dual drug-loaded niosomes showed a sustained drug release pattern up to 2 days. Acetylcholinesterase (AChE) and DPPH (1, 1-diphenyl-2- picrylhydrazyl) enzyme inhibition assays showed a better combinative effect than the free drug solutions. A 2-day nasal permeation proved the effectiveness and biocompatibility of the niosomes. In-vivo pharmacokinetic and organ biodistribution studies revealed a better drug profile and greater distribution of the niosomes in the brain compared to other organs, thereby indicating a direct nose-to-brain delivery of the niosomes.

Chondroitin Sulfate-Modified Liposomes for Targeted Co-Delivery of Doxorubicin and Retinoic Acid to Suppress Breast Cancer Lung Metastasis.

Breast cancer treatment remains challenging due to high levels of cell metastasis. Chemotherapy drug combinations can inhibit both tumor growth in situ and metastasis to distant organs. Therefore, here, we developed chondroitin sulfate liposomes (CSLs) as a carrier for the co-delivery of retinoic acid (RA) and doxorubicin (DOX) and examined their efficiency in suppressing lung metastasis of breast cancer. CSLs were prepared using CS–deoxycholic acid conjugates and found to encapsulate both RA and DOX via hydrophobic and hydrophilic interactions. The resulting DOX+RA-CSLs were uniformly spherical and showed good serum stability and encapsulation efficiency of 98.7% ± 1.3% for RA and 90.8% ± 2.9% for DOX. Pharmacodynamic experiments in vitro and in vivo also revealed that DOX+RA-CSLs had better anticancer and anti-metastatic activity than CS-free liposomes, single drug-loaded liposomes, and free drug solutions at the same dose (2 mg/kg DOX or RA). Our results suggest that this liposomal delivery system can effectively suppress lung metastasis of breast cancer.

Anticancer Activity of the Host-Guest Complex of Camptothecin with β-Cyclodextrin-Folate Conjugate. Encapsulation and Efficacy

Cyclodextrins are cyclic oligosachcharides that act as molecular hosts and accommodate drug molecules forming host: guest complexes. They aid in the sustained release of the encapsulated drugs through diffusion in solution and protect their unstable forms. In this paper, we report the synthesis of a β-cyclodextrin-folate by a simple coupling reaction. The compound is characterized using IR, NMR, and mass spectroscopic techniques. The amide carbonyl band is observed at 1680 cm-1. The mass spectrum shows the molecular ion peak of the β-cycloxetrin-folate conjugate at an m/z value of 1615.35. An inclusion complex of the anticancer drug, camptothecin, with the β-cycloxetrin-folate is formed on the stepwise addition of the β-cycloxetrin-folate to the guest molecule. The complex formation is studied using UV-visible and fluorescence spectroscopy. The formation of host: guest complexes is known to enable the sustained release of the encapsulated drug molecule. Herein, we examined the in vitro anticancer activity of the host: guest complex against cervical cancer (HeLa) cells. The host: guest complex formation results in enhanced efficacy of the drug. Dose-dependent cytotoxicity is observed for the β-cyclodextrin-folate: camptothecin complex. The cytotoxicity is more for the complex than for the free drug in solution.

Design of vincristine sulfate loaded poloxamer in situ nanogel: Formulation and in vitro evaluation

Vincristine is a naturally occurring anticancer drug with a specific mechanism of action, given intravenously/bolus to treat various types of cancers, including breast cancer. The present studies explored the potential of thermosensitive injectable nanogel of vincristine loaded nanoparticles. In situ gel was chosen as the delivery system because it restricts the unwanted exposure in blood and other healthy tissues, thus eliminate hemolytic side effects of the drug and offer easy administration in vivo. Furthermore, non-biodegradable and cytocompatible polymeric Eudragit RSPO nanoparticles are proposed as ideal candidates for biomedical usage. The method of preparation includes two major steps—the first formation of vincristine nanoparticles with positively charged Eudragit RSPO. In the second step, these nanoparticles were suspended into a thermosensitive gel base to act as an in situ nanogel. Characterization parameters performed are size, surface charge, vincristine sulfate release behavior and mechanism, polymer-drug interaction, and encapsulation efficiency. In situ nanogel was also evaluated for gelling time, drug release, hemocompatibility and cytotoxic activity in breast cancer MCF-7 cell lines. The magnitude of size (<200 nm) and unaltered presence of functional groups after nanoparticle preparation was confirmed by dynamic light scattering technique and FTIR resp. The desirable spherical contour and smooth surface of the prepared nanoparticles were confirmed by scanning electron microscopy. Almost 60% entrapment efficiency was obtained with the optimized batch. In MCF-7 cell lines, the in situ nanogel exhibited dose-dependent cytotoxic activity similar to free drug solution, which indicates incorporating the drug into nanogel does not deteriorate its cytotoxic activity. LD50 for in situ nanogel was 32.3 μg/mL and 12.9 μg/mL for the free drug.Furthermore, VS loaded in situ nanogels possessed less hemolytic activity than the pure drug. Hence, it can be concluded that thermo-receptive in situ nanogel of vincristine can be used to treat breast cancer cells with less hemolytic activity. Further in vivo studies are in progress to establish the effectiveness.

Optimization and characterization of tannic acid loaded niosomes for enhanced antibacterial and anti-biofilm activities

The purpose of this study was to prepare and characterize an optimized system of tannic acid-loaded niosomes as a potential carrier for antibacterial and anti-biofilm delivery. The niosomal formulation was optimized using response surface methodology (RSM). The effects of the molar ratio of surfactant to cholesterol, drug concentration, and molar ratio of Span 60 to Tween 60 on particle size and drug entrapment efficiency of the niosomal nanocarrier were studied. The optimized nanoparticles were characterized in terms of the morphology, in vitro release profile, and antibacterial properties. Moreover, Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) techniques were utilized to investigate drug-excipient interactions. Antibacterial and anti-biofilm activities of free tannic acid and tannic acid-loaded niosome were investigated against selected pathogenic bacteria including Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Furthermore, the expression level of biofilm-associated genes was evaluated in selected pathogenic bacteria using Real-Time PCR. According to the results, the dependent variables (particle size and entrapment efficiency) were best fitted to the quadratic model. The particle size and entrapment efficiency of the best niosomal formulation were 89 nm and 82%, respectively. The in vitro release of the optimized formulation showed a controlled release profile. Release kinetics indicated a diffusion-based release of the drug. FTIR and DSC studies also confirmed the absence of drug-excipient interactions. The optimized formulation exhibited higher antibacterial effects as compared with the free drug solution. Moreover, the time-kill assay of the encapsulated drug revealed a slow and controlled inhibition of bacterial growth for 72 h while the free drug was used up in the first hours. Moreover, tannic acid-loaded niosome reduced biofilm formation capacity in selected strains and down-regulated the biofilm gene expression as compared to free tannic acid.The optimized formulation containing tannic acid can be a promising candidate for designing a new delivery system for this antibacterial and anti-biofilm agent.

Co-Delivery of Hispolon and Doxorubicin Liposomes Improves Efficacy Against Melanoma Cells.

Hispolon is a small molecular weight polyphenol that has antioxidant, anti-inflammatory, and anti-proliferative activities. Our recent study has demonstrated hispolon as a potent apoptosis inducer in melanoma cell lines. Doxorubicin is a broad spectrum first-line treatment for various kinds of cancers. In this study, co-delivery of doxorubicin and hispolon using a liposomal system in B16BL6 melanoma cell lines for synergistic cytotoxic effects was investigated. Liposomes were prepared using a lipid film hydration method and loaded with doxorubicin or hispolon. The formulations were characterized for particle size distribution, release profile, and encapsulation efficiency (EE). In addition, in vitro cytotoxicity, in vitro cell apoptosis, and cellular uptake were evaluated. Liposomes exhibited small particle size (mean diameter ~ 100nm) and narrow size distribution (polydispersity index (< 0.2) and high drug EE% (> 90%). The release from liposomes showed slower release compared to free drug solution as an additional time required for the release of drug from the liposome lipid bilayer. Liposome loaded with doxorubicin or hispolon exhibited significantly higher cytotoxicity against B16BL6 melanoma cells as compared to doxorubicin solution or hispolon solution. Likewise, co-delivery of hispolon and doxorubicin liposomes showed two-fold and three-fold higher cytotoxicity, as compared to hispolon liposomes or doxorubicin liposomes, respectively. In addition, co-delivery of doxorubicin and hispolon in liposomes enhanced apoptosis more than the individual drugs in the liposome formulation. In conclusion, the co-delivery of hispolon and doxorubicin could be a promising therapeutic approach to improve clinical outcomes against melanoma.