Targeting prostate cancer with docetaxel-loaded peptide 563-conjugated PEtOx-co-PEI30%-b-PCL polymeric micelle nanocarriers.

Prostate cancer is a global disease that negatively affects the quality of life. Although various strategies against prostate cancer have been developed, only a few achieved tumor-specific targeting. Therefore, a special emphasis has been placed on the treatment of cancer using nano-carrier-encapsulated chemotherapeutic agents conjugated with tumor-homing peptides. The targeting strategy coupling the drugs with nanotechnology helps to overcome the most common barriers, such as high toxicity and side effects. Prostate-specific membrane antigen has emerged as a promising target molecule for prostate cancer and shown to be targeted with high affinity by GRFLTGGTGRLLRIS peptide known as peptide 563 (P563). Here, we aimed to assess the in vitro and in vivo targeting efficiency, safety, and efficacy of P563-conjugated, docetaxel (DTX)-loaded polymeric micelle nanoparticles (P563-PEtOx-co-PEI30%-b-PCL-DTX) against prostate cancer. To this end, we analyzed the cytotoxic activity of P563-PEtOx-co-PEI30%-b-PCL and P563-PEtOx-co-PEI30%-b-PCL-DTX by a cell proliferation assay using PNT1A and 22Rv1 cells. We have also determined the targeting selectivity of P563-PEtOx-co-PEI30%-b-PCL-FITC by flow cytometry and assessed the induction of cell death by western blot and TUNEL assays for P563-PEtOx-co-PEI30%-b-PCL-DTX in 22Rv1 cells. To investigate the in vivo efficacy, we administered DTX in the free form or in polymeric micelle nanoparticles to athymic CD-1 nu/nu mice 22Rv1 xenograft models and performed histopathological analyses. Our study showed that targeting prostate cancer with P563-conjugated PEtOx-co-PEI30%-b-PCL polymeric micelles could exert a potent anti-cancer activity with low side effects.

Cell culture and pharmacokinetic evaluation of a solid dosage formulation containing a water-insoluble orphan drug manufactured by FDM-3DP technology.

The in-vitro cytotoxicity, in-vitro permeability and in-vivo pharmacokinetics of a BCS Class-II drug - rufinamide - in a 3DP tablet formulation were evaluated. The cytotoxicity of the 3DP tablet formulation was evaluated with an MTT test; in-vitro permeability was evaluated with a Caco-2 cell culture study; and in-vivo pharmacokinetics were evaluated in Wistar albino male rats. The pharmacokinetic studies were performed following a two-sequence and single-period design approach. The highest Caco-2 permeability was obtained with the 3DP tablet formulation; and the highest cell viability was achieved with the 3DP tablet in both the Hep G2 and Caco-2 cell lines. In the in-vivo pharmacokinetic study, AUC and Cmax values were higher in the 3DP tablet formulation than in the Inovelon® film tablet at a 40 mg/kg dose. Thanks to the increased solubility of the active substance, higher in-vitro permeability and in-vivo absorption were achieved with the 3DP tablet formulation, and with lower cytotoxicity. Based on these promising findings, the 3DP tablet formulation can be considered an effective lower-dose treatment than commercial preparations.

The Nanosuspension Formulations of Daidzein: Preparation and In Vitro Characterization

Objectives: Daidzein (DZ), a water-insoluble isoflavone, has many beneficial effects (anti-inflammatory, antioxidant, and anticancer effects, etc.) on human health. DZ has a very low oral bioavailability related to its physicochemical properties (low solubility, intense metabolism of DZ in the intestine and liver). This study aimed to prepare and in vitro characterize the nanosuspension formulations of DZ to improve the poor solubility and efficacy of DZ. Materials and Methods: DZ nanosuspension formulations were prepared with media milling technique using zirconium oxide beads as milling media. Pluronic F127 and polyvinylpyrrolidone (PVP) K30 (formulation A; F-A) and sodium dodecyl sulfate (SDS) (SDS + pluronic F127 + PVP K30; formulation B; F-B) were used as stabilizers. The nanosuspension formulations were evaluated for morphological properties, particle sizes, zeta potential, DZ content, saturation solubility, dissolution, and their cytotoxic effects on RG2 glioblastoma tumor cells. Results: F-A and F-B formulations were nanosized (in the range of about 181-235 nm) and had negative zeta potential values before and after lyophilization. The DZ content of F-A and F-B formulations were found to be 93.68±0.78% and 89.75±0.49%, respectively. Fourier transform infrared spectroscopy analysis showed that there was no significant interaction between DZ and the excipients. Differential scanning calorimetry and X-ray diffraction analyses confirmed no change in the crystal structure of DZ in F-A and F-B formulations. Conclusion: In this study, the nanosuspension formulations were successfully prepared and characterized in vitro. Nanosuspension formulations increased the saturation solubility, dissolution rate, and cytotoxic effect of DZ.

Development and characterization of pullulan-based orally disintegrating films containing amlodipine besylate.

The aim of this study was to prepare pullulan-based orally disintegrating films (ODFs) containing amlodipine besylate, an anti-hypertensive drug, by the solvent casting method. For this purpose, nine different ODF formulations (F1-F9) were prepared by using different plasticizers (glycerol, sorbitol, propylene glycol) and different superdisintegrants (croscarmellose sodium, sodium starch glycolate, crospovidone). FD&C Green and aspartame were used as coloring agent and sweetener, respectively. According to the results of preformulation studies, the optimum ODF (F9) was determined and various characterization studies such as uniformity of mass, film thickness, surface pH of films, and mechanical properties (such as elongation at break, tensile strength, Young's modulus, and folding endurance), moisture content, disintegration time, uniformity of content and dissolution test, X-ray, DSC, SEM and short term stability analysis were performed on this formulation. Cytotoxicity and permeability studies for the F9 formulation were performed on the human epithelial colorectal adenocarcinoma (Caco-2) cell line. The formulation F9 had appropriate morphological and mechanical properties and disintegrated within 51.3 s according to the petri dish method, and 28.8 s according to the drop method. Dissolution studies revealed that 78.1 % of amlodipine besylate was dissolved in 20 min from F9 formulation. Cell culture studies showed that the formulation had no significant toxic effect on the Caco-2 cells. Also, there was no significant difference between the Caco-2 permeabilities of amlodipine besylate powder and amlodipine besylate ODFs. As a result of all these studies, we suggest to use the pullulan based amlodipine besylate ODFs to enhance ease of administration and patient compliance.

Formulation and In Vitro Evaluation of Telmisartan Nanoparticles Prepared by Emulsion-Solvent Evaporation Technique.

OBJECTIVES: Telmisartan (TLM) is an antihypertensive drug that has been shown to have antiproliferative effects on cancer cells. It has low solubility and suboptimal oral bioavailability. To investigate the potential anticancer effect of TLM on breast cancer cells, poly (D, L-lactide) (PLA) nanoparticles were formulated with the benefit of improving its solubility. MATERIALS AND METHODS: TLM-loaded PLA nanoparticles were prepared by emulsion solvent evaporation. The effects of sonication time and polymer:drug ratio on nanoparticle size and drug encapsulation were investigated. TLM-loaded nanoparticles were tested against MCF-7 and MD-AMB-231 breast cancer cell lines for antiproliferative effects. RESULTS: Nanoparticles with mean particle size 272 nm and 79% encapsulation efficiency were obtained. Sustained release TLM nanoparticles (40% in 24 h) decreased cell viability to 45% for MCF-7 cells at 72 h, even at the lowest TLM concentration, indicating better anticancer efficiency than TLM solution. CONCLUSION: TLM nanoparticles could be potential anticancer agents for breast cancer and deserve further studies.

Exploiting ionisable nature of PEtOx-co-PEI to prepare pH sensitive, doxorubicin-loaded micelles.

AIMS: This study was conducted to evaluate block copolymers containing two different poly(ethyleneimine) (PEI) amounts, as new pH-sensitive micellar delivery systems for doxorubicin. METHODS: Micelles were prepared with block copolymers consisting of poly(2-ethyl-2-oxazoline)-co-poly(ethyleneimine) (PEtOx-co-PEI) and poly(ε-caprolactone) (PCL) as hydrophilic and hydrophobic blocks, respectively. Doxorubicin loading, micelle size, pH-dependent drug release, and in vitro cytotoxicity on MCF-7 cells were investigated. RESULTS: The average size of drug-loaded micelles was under 100 nm and drug loading was between 10.7% and 48.3% (w/w). pH-sensitive drug release was more pronounced (84.7% and 68.9% (w/w) of drug was released at pH 5.0 and pH 7.4, respectively) for the micelles of the copolymer with the lowest PEI amount. The cell viability of doxorubicin-loaded micelles which were prepared by the copolymer with the lowest PEI amount was 28-33% at 72 h. CONCLUSIONS: PEtOx-co-PEI-b-PCL micelles of this copolymer were found to be stable and effective pH-sensitive nano-sized carriers for doxorubicin delivery.

Design of ocular drug delivery platforms and in vitro - in vivo evaluation of riboflavin to the cornea by non-interventional (epi-on) technique for keratoconus treatment.

AIM: Keratoconus is a common and progressive eye disease characterized by thinning and tapering of the cornea. This degenerative eye disease is currently treated in the clinic with an interventional technique ("epi-off") that can cause serious side effects as a result of the surgical procedure. The aim of this project is to design innovative formulations for the development of a riboflavin-containing medicinal product to develop a non-invasive ("epi-on") keratoconus treatment as an alternative to current treatment modalities. METHODS: Nanostructured lipid carriers (NLCs) were successfully loaded with either riboflavin base of riboflavin-5-phosphate sodium and designed with either Stearylamine (positive charge) or Trancutol P (permeation enhancer). In vitro characterization studies, cytotoxicity and permeability studies were performed. Selected formulations and commercial preparations were applied and compared in ex-vivo corneal drug accumulation and transition studies. Furthermore, in vivo studies were performed to assess drug accumulation in the rat cornea and the corneal stability after NLC treatment was investigated via a biomechanical study on isolated rabbit corneas. RESULTS: Both in vitro and ex-vivo as well as in vivo data showed that from the prepared NLC formulations, the most effective formulation was riboflavin-5-phosphate sodium containing NLC with Transcutol P as permeation enhancer. It possessed the highest drug loading content, low accumulation in the cornea but high permeability through the cornea as well as the highest functional performance in corneal crosslinking. CONCLUSION: Topical application of riboflavin-5-phosphate sodium loaded NLC systems designed with permeation enhancer Transcutol P may act as a potential alternative for non-invasive keratoconus treatments.

Development of an Anti-Inflammatory Drug-Incorporated Biomimetic Scaffold for Corneal Tissue Engineering.

Purpose: The aim of this study was to design naproxen sodium (NS)-containing, biomimetic, porous poly(lactide-co-glycolide) (PLGA) scaffolds for regeneration of damaged corneal epithelium. Methods: NS-incorporated PLGA scaffolds were prepared using the emulsion freeze-drying method and then coated with collagen or poly-l-lysine. Porosity measurements of the scaffolds were performed by the gas adsorption/desorption method and the scaffolds demonstrated highly porous, open-cellular pore structures with pore sizes from 150 to 200 µm. Results: The drug loading efficiency of scaffolds was found to be higher than 84%, and about 90%-98% of NS was released at the end of 7 days with a fast drug release rate at the initial period of time and then in a slow and sustained manner. The corneal epithelial cells were isolated from New Zealand white rabbits. The obtained cells were seeded onto scaffolds and continued to increase during the time period of the study, indicating that the scaffolds might promote corneal epithelial cell proliferation without causing toxic effects for at least 10 days. Conclusions: The NS-loaded PLGA scaffolds exhibited a combination of controlled drug release and biomimetic properties that might be attractive for use in treatment of corneal damage both for controlled release and biomedical applications.

Combination of Paclitaxel and R-flurbiprofen loaded PLGA nanoparticles suppresses glioblastoma growth on systemic administration.

Malignant gliomas are highly lethal. Delivering chemotherapeutic drugs to the brain in sufficient concentration is the major limitation in their treatment due to the blood-brain barrier (BBB). Drug delivery systems may overcome this limitation and can improve the transportation through the BBB. Paclitaxel is an antimicrotubule agent with effective anticancer activity but limited BBB permeability. R-Flurbiprofen is a nonsteroidal antienflammatory drug and has potential anticancer activity. Accordingly, we designed an approach combining R-flurbiprofen and paclitaxel and positively-charged chitosan-modified poly-lactide-co-glycolic acid (PLGA) nanoparticles (NPs) and to transport them to glioma tissue. NPs were characterized and, cytotoxicity and cellular uptake studies were carried out in vitro. The in vivo efficacy of the combination and formulations were evaluated using a rat RG2 glioma tumor model. Polyethylene glycol (PEG) modified and chitosan-coated PLGA NPs demonstrated efficient cytotoxic activity and were internalized by the tumor cells in RG2 cell culture. In vivo studies showed that the chitosan-coated and PEGylated NPs loaded with paclitaxel and R-flurbiprofen exhibited significantly higher therapeutic activity against glioma. In conclusion, PLGA NPs can efficiently carry their payloads to glioma tissue and the combined use of anticancer and anti-inflammatory drugs may exert additional anti-tumor activity.

Preparation, characterization and pharmacokinetic evaluation of rosuvastatin calcium incorporated cyclodextrin-polyanhydride nanoparticles.

Objective: The aim of the study was to formulate, cyclodextrin (CD)-polyanhydride (PA) nanoparticles (CPNs) with rosuvastatin calcium (RCa) in order to enhance the poor oral bioavailability. Methods: CPNs containing RCa/CD complexes were prepared by a modified solvent displacement method and morphological analyses, particle size (PS), polydispersity index (PDI), zeta potential (ZP), encapsulation efficiency (EE), DSC, FT-IR, XRD, 1H-NMR analyses were performed. In vitro release properties, release kinetics, cytotoxicity, in vitro permeability and pharmacokinetic studies were also studied. The stability of the formulations were evaluated during the storage period of 3 months. Results: The physicochemical studies showed that the RCa/CD complexes were well incorporated into CPNs resulted in nanosized particles (215.22 and 189.13 nm) with homogenous size distribution (PDI: 0.203 and 0.182) with relatively high incorporation capacity (76.11 and 68.18%) for the CPN1 and CPN2 formulations respectively. Sustained release of RCa from CPNs were achieved. The cytotoxicity values showed that the safety of the formulations. According to permeability studies, pure RCa had lowest permeability data (3.08 × 10-7 cm⋅s-1 Papp value) while CPNs gained higher permeability data (1.36 × 10-5 and 1.12 × 10-5 cm⋅s-1 Papp values) for the CPN1 and CPN2 formulations respectively. CPN2 formulation was selected for pharmacokinetic studies and analyses results demonstrated that approximately 8-fold relative oral bioavailability enhancement compared to the pure RCa was achieved. Conclusion: Considering the analyses results of the study, CPNs can be regarded as suitable, safe, functional oral delivery systems for RCa with enhanced oral bioavailability.

Development of novel self-assembled polymeric micelles from partially hydrolysed poly(2-ethyl-2-oxazoline)-co-PEI-b-PCL block copolymer as non-viral vectors for plasmid DNA in vitro transfection.

A new efficient, non-viral gene delivery cationic polymeric micellar system was developed by partial hydrolysis of poly(2-ethyl-2-oxazoline) (PEtOx) with two different hydrolysis percentages of PEtOx (30% and 60%) to reduce the disadvantages of the PEI. These self-assemble amphiphilic cationic micelles prepared from poly(2-ethyl-2-oxazoline)30%-co-poly(ethyleneimine)-block-poly(ɛ-caprolactone) (PEtOx30%-co-PEI-b-PCL) (PPP30) and poly(2-ethyl-2-oxazoline) 60%-co-poly(ethyleneimine)-block-poly(ɛ-caprolactone) (PEtOx60%-co-PEI-b-PCL) (PPP60) block copolymers were successfully condensed with pEGFP-C3 plasmid DNA via electrostatic interactions to form micelle/DNA complexes with desirable particle sizes. All formulations showed low critical micelle concentration (CMC) values that means highly stable in serum containing medium. Polymeric micelles were also evaluated for their stability in the presence of serum and nuclease as well as cytotoxicity and transfection efficiency. All our results proved that our novel polymeric micellar system prepared by PPP60 block copolymer offer to be an efficient promising carrier for gene delivery applications. Moreover, these findings contribute to design and development of novel gene vectors with tunable and functionality features and also to reduce the cytotoxicity of PEI by partial hydrolysis of PEtOx an alternative synthesis method to produce linear PEI.

Development and evaluation of orally disintegrating tablets comprising taste-masked mirtazapine granules.

INTRODUCTION: Orally disintegrating tablets (ODTs) provide an important treatment option for pediatric, geriatric and psychiatric patients. In our previous study, we have performed the initial studies for the formulation development and characterization of new ODT formulations containing a bitter taste drug, mirtazapine, coated with 6% (w/w) Eudragit® E-100 (first group of formulations, FGF) without taste evaluation. In present study, coating ratio of the drug was increased to 8% (w/w) (second group of formulations, SGF) to examine the effect of increased coating ratio of drug on in vitro characterization of the formulations including in vitro taste masking study. MATERIALS AND METHODS: Coacervation technique using Eudragit® E-100 was employed to obtain taste-masked mirtazapine granules. FGF and SGF were compared to original product (Remeron SolTab, an antidepressant drug which produced by pellet technology) in terms of in vitro permeability, in vitro taste masking efficiency which was performed by dissolution studies in salivary medium and dissolution stability. Also, the other tablet characteristics (such as diameter, thickness) of SGF were examined. RESULTS AND DISCUSSION: The disintegration time of the SGF were found as A1 < A2 < A3 < A5 < A4 (8% Eudragit® E-100), but all of the formulations dissolved under 30 seconds and friability values were less than 1%. In vitro taste masking efficiency studies demonstrated that C2 formulation (in FGF) had the most similar dissolution profile to Remeron SolTab. CONCLUSIONS: According to these findings, B2 or C2 (with citric acid or sodium bicarbonate, respectively, with 6% Eudragit® E-100) formulations could be promising alternatives to Remeron SolTab.

A potential non-invasive glioblastoma treatment: Nose-to-brain delivery of farnesylthiosalicylic acid incorporated hybrid nanoparticles.

New drug delivery systems are highly needed in research and clinical area to effectively treat gliomas by reaching a high antineoplastic drug concentration at the target site without damaging healthy tissues. Intranasal (IN) administration, an alternative route for non-invasive drug delivery to the brain, bypasses the blood-brain-barrier (BBB) and eliminates systemic side effects. This study evaluated the antitumor efficacy of farnesylthiosalicylic acid (FTA) loaded (lipid-cationic) lipid-PEG-PLGA hybrid nanoparticles (HNPs) after IN application in rats. FTA loaded HNPs were prepared, characterized and evaluated for cytotoxicity. Rat glioma 2 (RG2) cells were implanted unilaterally into the right striatum of female Wistar rats. 10days later, glioma bearing rats received either no treatment, or 5 repeated doses of 500µM freshly prepared FTA loaded HNPs via IN or intravenous (IV) application. Pre-treatment and post-treatment tumor sizes were determined with MRI. After a treatment period of 5days, IN applied FTA loaded HNPs achieved a significant decrease of 55.7% in tumor area, equal to IV applied FTA loaded HNPs. Herewith, we showed the potential utility of IN application of FTA loaded HNPs as a non-invasive approach in glioblastoma treatment.

Farnesylthiosalicylic acid-loaded lipid-polyethylene glycol-polymer hybrid nanoparticles for treatment of glioblastoma.

OBJECTIVES: We aimed to develop lipid-polyethylene glycol (PEG)-polymer hybrid nanoparticles, which have high affinity to tumour tissue with active ingredient, a new generation antineoplastic drug, farnesylthiosalicylic acid (FTA) for treatment of glioblastoma. METHOD: Farnesylthiosalicylic acid-loaded poly(lactic-co-glycolic acid)-1,2 distearoyl-glycerol-3-phospho-ethanolamine-N [methoxy (PEG)-2000] ammonium salt (PLGA-DSPE-PEG) with or without 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) hybrid nanoparticles has been prepared and evaluated for in-vitro characterization. Cytotoxicity of FTA-loaded nanoparticles along with its efficacy on rat glioma-2 (RG2) cells was also evaluated both in vitro (in comparison with non-malignant cell line, L929) and in vivo. KEY FINDINGS: Scanning electron microscopy studies showed that all formulations prepared had smooth surface and spherical in shape. FTA and FTA-loaded nanoparticles have cytotoxic activity against RG2 glioma cell lines in cell culture studies, which further increases with addition of DOTAP. Magnetic resonance imaging and histopathologic evaluation on RG2 tumour cells in rat glioma model (49 female Wistar rats, 250-300 g) comparing intravenous and intratumoral injections of the drug have been performed and FTA-loaded nanoparticles reduced tumour size significantly in in-vivo studies, with higher efficiency of intratumoral administration than intravenous route. CONCLUSION: Farnesylthiosalicylic acid-loaded PLGA-DSPE-PEG-DOTAP hybrid nanoparticles are proven to be effective against glioblastoma in both in-vitro and in-vivo experiments.

Dry powders for the inhalation of ciprofloxacin or levofloxacin combined with a mucolytic agent for cystic fibrosis patients.

OBJECTIVE: This study aimed to design and characterize an inhalable dry powder of ciprofloxacin or levofloxacin combined with the mucolytics acetylcysteine and dornase alfa for the management of pulmonary infections in patients with cystic fibrosis. METHODS: Ball milling, homogenization in isopropyl alcohol and spray drying processes were used to prepare dry powders for inhalation. Physico-chemical characteristics of the dry powders were assessed via thermogravimetric analysis, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry and scanning electron microscopy. The particle size distribution, dissolution rate and permeability across Calu-3 cell monolayers were analyzed. The aerodynamic parameters of dry powders were determined using the Andersen cascade impactor (ACI). RESULTS: After the micronization process, the particle sizes of the raw materials significantly decreased. X-ray and DSC results indicated that although ciprofloxacin showed no changes in its crystal structure, the structure of levofloxacin became amorphous after the micronization process. FT-IR spectra exhibited the characteristic peaks for ciprofloxacin and levofloxacin in all formulations. The dissolution rates of micro-homogenized and spray-dried ciprofloxacin were higher than that of untreated ciprofloxacin. ACI results showed that all formulations had a mass median aerodynamic diameter less than 5 µm; however, levofloxacin microparticles showed higher respirability than ciprofloxacin powders did. The permeability of levofloxacin was higher than those of the ciprofloxacin formulations. CONCLUSION: Together, our study showed that these methods could suitably characterize antibiotic and mucolytic-containing dry powder inhalers.

New azole derivatives showing antimicrobial effects and their mechanism of antifungal activity by molecular modeling studies.

Azole antifungals are potent inhibitors of fungal lanosterol 14α demethylase (CYP51) and have been used for eradication of systemic candidiasis clinically. Herein we report the design, synthesis, and biological evaluation of a series of 1-phenyl/1-(4-chlorophenyl)-2-(1H-imidazol-1-yl)ethanol esters. Many of these derivatives showed fungal growth inhibition at very low concentrations. Minimal inhibition concentration (MIC) value of 15 was 0.125 µg/mL against Candida albicans. Additionally, some of our compounds, such as 19 (MIC: 0.25 µg/mL), were potent against resistant C. glabrata, a fungal strain less susceptible to some first-line antifungal drugs. We confirmed their antifungal efficacy by antibiofilm test and their safety against human monocytes by cytotoxicity assay. To rationalize their mechanism of action, we performed computational analysis utilizing molecular docking and dynamics simulations on the C. albicans and C. glabrata CYP51 (CACYP51 and CGCYP51) homology models we built. Leu130 and T131 emerged as possible key residues for inhibition of CGCYP51 by 19.

Design and In Vitro Evaluation of Bispecific Complexes and Drug Conjugates of Anticancer Peptide, LyP-1 in Human Breast Cancer.

PURPOSE: LyP-1, a nine-amino-acid tumor homing peptide, selectively binds to its cognate receptor, p32. Overexpression of p32 in certain tumors should allow use of LyP-1 as a targeting agent for the delivery of therapeutic or diagnostic agents. Peptide conjugates are developed for enhanced pre-targeting of MDA-MB-231 breast cancer cells with peptide-antibody bispecific complexes and targeting with multiple-drug/-fluorophore-conjugated nano-polymers. METHODS: LyP-1-anti-DTPA bispecific antibody complexes (LyP-1-bsAbCx) were generated by conjugation of anti-DTPA antibody and LyP-1. LyP-1-doxorubicin (Dox), Dox-DTPA-succinyl-polylysine (Dox-DSPL), Dox-DSPL-LyP-1, DTPA-Dox-poly glutamic acid (D-Dox-PGA) or DTPA-rhodamine conjugated polylysine (DSPL-RITC) were prepared. In vitro therapeutic efficacy and targeting by immunofluorescence in MDA-MB-231 breast cancer cells were assessed with Dox-LyP-1. Immunofluorescence visualization of cancer cells was evaluated after pretargeting with LyP-1-bsAbCx and targeting with DSPL-RITC. RESULTS: Cytotoxicity of Dox-LyP-1 conjugates was significantly greater than free doxorubicin (p < 0.0001). For fluorescent-labeled LyP-1, internalization occurred in 30 min in tumor cells. Fluorescence intensity of two-step targeted cells showed that pretargeting with LyP-1-bsAbC, followed by targeting with DSPL-RITC was greater than non-pretargeted DSPL-RITC (p < 0.05). CONCLUSIONS: Peptide-conjugates are effective targeting agents for MDA-MB-231 breast cancer cells in culture. LyP-1-bsAbCx and Dox-LyP-1 conjugates may allow development of novel targeted cancer therapy and diagnosis.

Dexamethasone - PAMAM dendrimer conjugates for retinal delivery: preparation, characterization and in vivo evaluation.

OBJECTIVE: Ocular diseases affecting retina, such as diabetic retinopathy (DR), age-related macular degeneration (AMD) and glaucoma are the major causes of blindness, and their treatment is still a challenge due to the special structure of the eye. The purpose of this study was to prepare a sustained release DEX conjugate formulation with enhanced ocular permeation using poly(amidoamine) (PAMAM) dendrimers and to evaluate the effects of conjugation on DEX release and ocular residence time. METHODS: PAMAM G3.5 and PAMAM G4.5 dendrimers were used to prepare DEX conjugates, and conjugation was confirmed using (1) H-NMR. Formulations were evaluated in terms of drug release in the presence of ocular enzymes and cytotoxicity on ARPE19 cell lines. Fluorotron analysis was performed and ocular pharmacokinetic properties of DEX-PAMAM conjugates were studied in Sprague Dawley rats following intravitreal and subconjunctival applications. KEY FINDINGS: The results indicated that DEX-PAMAM conjugates were able to enhance ocular permeability and ocular tissue levels of DEX following subconjunctival injection, and results were encouraging when compared to the literature that has reported DEX getting cleared from vitreous in 3 h. CONCLUSION: Current studies are focused on formulation improvement to enhance hydrolysis and clearance time.

Lysozyme-loaded lipid-polymer hybrid nanoparticles: preparation, characterization and colloidal stability evaluation.

CONTEXT: Lipid-polymer hybrid nanoparticles (LPNPs) are polymeric nanoparticles enveloped by lipid layers, which have emerged as a potent therapeutic nanocarrier alternative to liposomes and polymeric nanoparticles. OBJECTIVE: The aim of this work was to develop, characterize and evaluate LPNPs to deliver a model protein, lysozyme. MATERIALS AND METHODS: Lysozyme-loaded LPNPs were prepared by using the modified w/o/w double-emulsion-solvent-evaporation method. Poly-ɛ-caprolactone (PCL) was used as polymeric core material and tripalmitin:lechitin mixture was used to form a lipid shell around the LPNPs. LPNPs were evaluated for particle size distribution, zeta potential, morphology, encapsulation efficiency, in vitro drug release, stability and cytotoxicity. RESULTS: The DLS measurement results showed that the particle size of LPNPs ranged from 58.04 ± 1.95 nm to 2009.00 ± 0.52 nm. The AFM and TEM images of LPNPs demonstrate that LPNPs are spherical in shape. The protein-loading capacity of LPNPs ranged from 5.81% to 60.32%, depending on the formulation parameters. LPNPs displayed a biphasic drug release pattern with a burst release within 1 h, followed by sustained release afterward. Colloidal stability results of LPNPs in different media showed that particle size and zeta potential values of particles did not change significantly in all media except of FBS 100% for 120 h. Finally, the results of a cellular uptake study showed that LPNPs were significantly taken up by 83.3% in L929 cells. CONCLUSION: We concluded that the LPNPs prepared with PCL as polymeric core material and tripalmitin:lechitin mixture as lipid shell should be a promising choice for protein delivery.

In Vitro/In Vivo Evaluation of Dexamethasone--PAMAM Dendrimer Complexes for Retinal Drug Delivery.

Current treatment options for diabetic retinopathy (DR) have side effects because of invasive application and topical application does not generally result in therapeutic levels in the target tissue. Therefore, improving the drug delivery to retina, following topical administration, might be a solution to DR treatment problems. The purpose of this study was to investigate the complexation effects of poly(amidoamine) (PAMAM) dendrimers on ocular absorption of dexamethasone (DEX). Using different PAMAM generations, complex formulations were prepared and characterized. Formulations were evaluated in terms of cytotoxicity and cell permeability, as well as ex vivo transport across ocular tissues. The ocular pharmacokinetic properties of DEX formulations were studied in Sprague-Dawley rats following topical and subconjunctival applications, to evaluate the effect of PAMAM on retinal delivery of DEX. Methyl-thiazol-tetrazolium (MTT) assay indicated that all groups resulted in cell viability comparable to DEX solution (87.5%), with the cell viability being the lowest for G3 complex at 73.5%. Transport study results showed that dendrimer complexation increases DEX transport across both cornea and sclera tissues. The results of in vivo studies were also indicated that especially anionic DEX-PAMAM complex formulations have reached higher DEX concentrations in ocular tissues compared with plain DEX suspension.