Losartan in Situ Forming Gel as a New Treatment for Hypertrophic Scars.

Hypertrophic scars are defined as visible lesions formed by excessive wound healing that cause cosmetic and, in some cases, functional challenges in patients. This study aimed to assess the efficacy of intralesional injections of losartan-loaded in situ forming gel and compare it with the common treatment (triamcinolone) in preventing scar formation. The formulation was prepared using a thermosensitive PLGA-PEG-PLGA triblock copolymer. Ear scar tissue in rabbits represented the hypertrophic scar, and the animals were treated with three treatments in three groups. Nine weeks following the single treatment, images of the scars were obtained and quantitatively analyzed using ImageJ and light microscopy was used to evaluate the fibroblast cell number, vascularization, inflammation and collagen deposition and fibrosis in H&E-stained sample tissue. According to the results based on the ImageJ and the Vancouver criteria, the losartan in situ forming gel (F-LG) indicated significantly higher improving effects on decreased vascularity and pigmentation in comparison with triamcinolone (F-TA) and placebo as a control (F-Ctl), although the effect F-LG was almost similar to F-TA on pliability and scar height, and they were better than the control. Histological findings showed F-LG and F-TA have less inflammatory and fibroblast cells compared to F-Ctl. Also, results indicated the dermal layers of the F-TA and F-LG groups' scar were thinner, and the deposition of collagens was reduced compared to the control. Consequently, F-LG was found to be an effective treatment in reducing scarring and promoting wound healing.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Delivery of disulfiram into breast cancer cells using folate-receptor-targeted PLGA-PEG nanoparticles: in vitro and in vivo investigations.

BACKGROUND: A folate-receptor-targeted poly (lactide-co-Glycolide) (PLGA)-Polyethylene glycol (PEG) nanoparticle is developed for encapsulation and delivery of disulfiram into breast cancer cells. After a comprehensive characterization of nanoparticles, cell cytotoxicity, apoptosis induction, cellular uptake and intracellular level of reactive oxygen species are analyzed. In vivo acute and chronic toxicity of nanoparticles and their efficacy on inhibition of breast cancer tumor growth is studied. RESULTS: The folate-receptor-targeted nanoparticles are internalized into the cells, induce reactive oxygen species formation, induce apoptosis and inhibit cell proliferation more efficiently compared to the untargeted nanoparticles. The acute and toxicity test show the maximum dose of disulfiram equivalent of nanoparticles for intra-venous injection is 6 mg/kg while show significant decrease in the breast cancer tumor growth rate. CONCLUSION: It is believed that the developed formulation could be used as a potential vehicle for successful delivery of disulfiram, an old and inexpensive drug, into breast cancer cells and other solid tumors.

Development of osteon-like scaffold-cell construct by quadruple coaxial extrusion-based 3D bioprinting of nanocomposite hydrogel.

Despite advances in bone tissue engineering, fabricating a scaffold which can be used as an implant for large bone defects remains challenge. One of the great importance in fabricating a biomimetic bone implant is considering the possibility of the integration of the structure and function of implants with hierarchical structure of bone. Herein, we propose a method to mimic the structural unit of compact bone, osteon, with spatial pattern of human umbilical vein endothelial cells (HUVECs) and human mesenchymal stem cells (hMSCs) in the adjacent layers that mimic Haversian canal and lamella, respectively. To this end, coaxial extrusion-based bioprinting technique via a customized quadruple-layer core-shell nozzle was employed. 3D implant scaffold-cell construct was fabricated by using polyethylene glycol as a hollowing agent in the first layer, gelatin methacryloyl (GelMA) and alginate blended hydrogel encapsulating HUVEC cells with vascular endothelial growth factor nanoparticles in the second layer (vasculogenic layer) to mimic vascular vessel, and GelMA and alginate blended hydrogel containing hMSCs cells in the outer osteogenic layer to imitate lamella. Two types of bone minerals, whitlockite and hydroxyapatite, were incorporated in osteogenic layer to induce osteoblastic differentiation and enhance mechanical properties (the young's modules of nanocomposite increased from 35 kPa to 80 kPa). In-vitro evaluations demonstrated high cell viability (94 % within 10 days) and proliferation. Furthermore, ALP enzyme activity increased considerably within 2 weeks and mineralized extra cellular matrix considerably produced within 3 weeks. Also, a significant increase in osteogenic markers was observed indicating the presence of differentiated osteoblast cells. Therefore, the work indicates the potential of single step 3D bioprinting process to fabricate biomimetic osteons to use as bone grafts for regeneration.

Molecularly imprinted nanoparticles prepared by miniemulsion polymerization as selective receptors and new carriers for the sustained release of carbamazepine.

Water-compatible imprinted nanoparticles were prepared for carbamazepine as a template and used for the selective extraction and controlled release of carbamazepine. Assay materials and drug delivery carriers were typically used in aqueous environments, so it is generally preferable to prepare solvent-free molecularly imprinted nanoparticles in water using the miniemulsion polymerization method. The present work investigates a bio-analytical strategy generically applicable to imprinted materials for molecular recognition studies, including equilibrium and non-equilibrium binding, and release experiments, increasing the knowledge of the molecular interactions between the template molecules and imprinted nanoparticles. The results showed that the imprinted nanoparticles exhibited a higher binding level and slower release rate than non-imprinted nanoparticles. The selectivity of imprinted nanoparticles for carbamazepine studied in comparison with an analogue compound, oxcarbazepine, the main metabolite of carbamazepine. The recovery and selectivity of carbamazepine in human serum was determined to be 100%, 1.7 times that of oxcarbazepine. The results indicated that carbamazepine-imprinted nanoparticles are appropriate for serum level determination of the drug in therapeutic range. The template to functional monomer ratio as a key factor controlling the recognition and release kinetic mechanism of imprinted nanoparticles is discussed. The imprinted nanoparticles prepared at the appropriate template to functional monomer mole ratio (2:8) exhibited the best drug affinity (5.1 times higher) and a slower drug release rate due to the interaction of carbamazepine with the imprinted cavities within the nanoparticles. Loaded imprinted nanoparticles as drug reservoirs were able to prolong carbamazepine release, in 1% wt sodium dodecyl sulfate aqueous solution, for more than 8 days.

Novel biodegradable molecularly imprinted polymer nanoparticles for drug delivery of methotrexate anti-cancer; synthesis, characterization and cellular studies.

BACKGROUND: Recently biodegradable nanoparticles are the center of attention for the development of drug delivery systems. Molecularly imprinted polymer (MIP) is an interesting candidate for designing drug nano-carriers. MIP-based nanoparticles could be used for cancer treatment and exhibited the potential to fill gaps regarding to ligand-based nanomaterials. Also, the presence of a cross-linker can play an essential role in nanoparticle stability and physicochemical properties of nanoparticles after synthesis. OBJECTIVES: In this research, a biodegradable drug delivery system based on MIP nanoparticles was prepared using a biodegradable cross-linker (dimethacryloyl hydroxylamine, DMHA) for methotrexate (MTX). A hydrolysable functional group CO-O-NH-CO was added to the crosslinking agent to increase the final biodegradability of the polymer. METHODS: Firstly, a biodegradable cross-linker was synthesized. Then, the non-imprinted polymers were prepared through mini-emulsion polymerization in the absence of a template; and efficient particle size distribution was determined. Finally, methotrexate was placed in imprinted polymers to achieve the desired MIP. Different types of MIPs were synthesized using different molar ratios of template, cross-linker, and functional monomer, and the optimal molar ratio was obtained at 1:4:20, respectively. RESULTS: HNMR successfully confirmed the chemical structure of the cross-linker. According to SEM images, nanoparticles had a spherical shape with a smooth surface. The imprinted nanoparticles showed a narrow size distribution with an average of 120 nm at a high ratio of cross-linker. The drug loading and entrapment efficiency were 6.4% and 92%, respectively. The biodegradability studies indicated that the nanoparticles prepared by DMHA had a more degradability rate than ethylene glycol dimethacrylate as a conventional cross-linker. Also, the polymer degradation rate was higher in alkaline environments. Release studies in physiological and alkaline buffer showed an initial burst release of a quarter of loaded MTX during the day and a 70% release during a week. The Korsmeyer-Peppas model described the release pattern. The cytotoxicity of MTX loaded in nanoparticles was studied on the MCF-7 cell line, and the IC50 was 3.54 µg/ml. CONCLUSION: It was demonstrated that nanoparticles prepared by DMHA have the potential to be used as biodegradable drug carriers for anticancer delivery. Synthesis schema of molecular imprinting of methotrexate in biodegradable polymer based on dimethacryloyl hydroxylamine cross-linker, for use as nanocarrier anticancer delivery to breast tumor.

Impact of oxygen-calcium-generating and bone morphogenetic protein-2 nanoparticles on survival and differentiation of bone marrow-derived mesenchymal stem cells in the 3D bio-printed scaffold.

Although stem cell therapy is a major area of interest in tissue engineering, providing proper oxygen tension, good viability, and cell differentiation remain challenges in tissue-engineered scaffolds. In this study, an osteogenic scaffold was fabricated using the 3D bio-printing technique. The bio-ink contained alginate hydrogel, encapsulated human bone marrow-derived mesenchymal stem cells (hBM-MSCs), calcium peroxide nanoparticles (CPO NPs) as an oxygen generating biomaterial, and bone morphogenic protein-2 nanoparticles (BMP2 NPs) as an osteoinductive growth factor. CPO NPs were synthesized with the hydrolysis-precipitation method, and their concentrations in the bio-ink were optimized. Scaffolds containing CPO 3% (w/w) were preferred, because they generated sufficient oxygen gas for 20 days, increased mechanical strength after 20 days, and had sufficient stability. The CPO NPs effect on the viability of embedded hBM-MSCs under hypoxic conditions was analyzed. Live/Dead staining results represented a 22% improvement in CPO 3% scaffold viability on day 7. Therefore, CPO NPs constituted a promising survival factor. BMP2 NPs were prepared with the double emulsification technique. The incorporation of both BMP2 and CPO NPs resulted in the upregulation of Runt-related transcription factor 2, Collagen type I alpha 1, and the osteocalcin genes compared to internal references in osteogenic media. Overall, the proposed 3D bio-printed osteogenic scaffold in this study has moved scientific research one step forward toward successful stem cell therapy and helped improve host tissue healing by biological activity enhancement, especially for low oxygen pressure tissues.

S2P peptide-conjugated PLGA-Maleimide-PEG nanoparticles containing Imatinib for targeting drug delivery to atherosclerotic plaques.

BACKGROUND: Imatinib is a platelet-derived growth factor receptor (PDGFR) inhibitor with very low water solubility. Previous studies in atherosclerosis have shown that PDGFR activity has an egregious effect on vascular disease and progression of atherosclerosis. Specific ligands of atherosclerotic plaques can be used for targeting of nanoparticles. Studies in atherosclerosis proved that stabilin-2 is a glycoprotein which exists abundantly in atherosclerotic plaques and it is produced from both macrophages and endothelial cells. OBJECTIVES: The objective of this study is the targeting drug delivery to atherosclerotic plaques by using imatinib-loaded nanoparticles modified by S2P peptide. METHODS: The imatinib-loaded nanoparticles were fabricated through a modified emulsion/solvent evaporation technique. After fabricating PLGA nanoparticles, maleimide PEG was used as linker between PLGA nanoparticles and S2P peptide. Because of presence cysteine in both side of S2P peptide, maleimide formed a thiolether linkage by thiol group of cysteine. Then the physicochemical analysis like H-NMR, FT-IR, DSC, SEM, particle size, zeta potential, and drug release were studied. RESULTS: Stabilin-2 peptide with sequence of CRTLTVRKC is a specific ligand to stabilin-2, so it was synthesized for using as the targeting agent for atherosclerosis. S2P peptide conjugation to the surface of nanoparticles was proved by H-NMR and FT-IR, and the percentage of S2P peptide in nanoparticles was 1.3%. The final nanoparticles were spherical and their size were 183 nm. The loading capacity of the imatinib-loaded nanoparticles was 5.05%. The sustained release profile was observed for peptide targeted nanoparticles. CONCLUSION: The chosen method was simple, reproducible, and specific in peptide conjugation of nanoparticles for targeting delivery to atherosclerotic regions. Graphical abstract .

Preparation and Characterization of Albumin Nanoparticles of Paclitaxel-Triphenylphosphonium Conjugates: New Approach to Subcellular Targeting.

Mitochondria have been recognized as important targets in cancer therapy due to their role in the respiratory process of cells. One approach employed for mitochondrion targeting is conjugation of a delocalized cation such as triphenylphosphonium (TPP), with antineoplastic agents, for instance paclitaxel (PTX). In cell cytoplasm, TPP-PTX can come close to mitochondria due to its high positive charge, which has a strong tendency toward the enhanced negative charge of mitochondria. The esteric bond of TPP-PTX can break down in the acidic environment of tumor cells and release the PTX, which can act directly on mitochondria to kill tumor cells. TPP-PTX was synthesized in three steps: Succinic anhydride (SUC) reacted with PTX to achieve succinyl paclitaxel (SUC-PTX), which has an acid-labile esteric bond. Then 2-triphenylphosphonium ethylammonium (ATPP) was prepared by attaching 2-bromoethylammunium bromide to TPP. Finally, a TPP-PTX prodrug was synthesized by attaching these materials. The products of all steps were characterized by thin-layer chromatography (TLC), infrared spectroscopy (IR), and nuclear magnetic resonance (1H NMR, 13C NMR). The purity of the products was determined by HPLC methods. TPP-PTX, as a prodrug, was loaded in to human serum albumin (HSA) nanoparticles by a method inspired by nab-technology with 130-160 nm particle size distribution, PdI=0.166 and Zeta potential -12.6 mV.

Synthetic and biological identities of polymeric nanoparticles influencing the cellular delivery: An immunological link.

Enhanced understanding of bio-nano interaction requires recognition of hidden factors such as protein corona, a layer of adsorbed protein around nano-systems. This study compares the biological identity and fingerprint profile of adsorbed proteins on PLGA-based nanoparticles through nano-liquid chromatography-tandem mass spectrometry. The total proteins identified in the corona of nanoparticles (NPs) with different in size, charge and compositions were classified based on molecular mass, isoelectric point and protein function. A higher abundance of complement proteins was observed in modified NPs with an increased size, while NPs with a positive surface charge exhibited the minimum adsorption for immunoglobulin proteins. A correlation of dysopsonin/opsonin ratio was found with cellular uptake of NPs exposed to two positive and negative Fc receptor cell lines. Although the higher abundance of dysopsonins such as apolipoproteins may cover the active sites of opsonins causing a lower uptake, the correlation of adsorbed dysopsonin/opsonin proteins on the NPs surface has an opposite trend with the intensity of cell uptake. Despite the reduced uptake of corona-coated NPs in comparison with pristine NPs, the dysopsonin/opsonin ratio controlled by the physicochemistry properties of NPs could potentially be used to tune up the cellular delivery of polymeric NPs.

Targeted Delivery of Cabazitaxel by Conjugation to Albumin-PEG-folate Nanoparticles Using a Cysteine-acrylate Linker and Simple Synthesis Conditions.

BACKGROUND: Cabazitaxel (CBZ) is a new taxane approved by FDA for treatment of castration- resistant prostate cancer not responding to docetaxel. However, CBZ is not a suitable substrate for p-glycoprotein 60, an efflux pump which transports anticancer drugs out of malignant cells and is therefore a promising drug for treatment of multidrug resistant tumors. Similar to other taxanes, the presence of Tween 80 in the CBZ formulation shows that it is insoluble in water. METHODS: In order to increase the solubility and circulation time of this drug, CBZ-human serum albumin (HSA) conjugate was synthesized. The designed linker was composed of methacrylic acid and N-acetyl cysteine to increase the solubility of CBZ and to increase the efficiency of conjugation. Targeting was performed by poly(ethylene glycol)-folic acid amide bound formation with carboxyl groups of HSA during in the step of nanoparticle formation. Cytotoxicity of nanoparticles was evaluated in vitro on HT-29, as a folate negative cell line, and MDA-MB-231, as a folate positive cell line. RESULTS: H-NMR, Gel Permeation Chromatography, High Pressure Liquid Chromatography and UV spectrophotometry analysis confirmed the composition of conjugates. The resulting nanoparticles had a spherical shape, narrow size distribution and mean diameter of 138 nm. The efficiency of conjugation was 41.6 %. The IC50 of CBZ in targeted nanoparticles was 10.1 and 17.4% lower than that of the free CBZ for HT-29 and MDA-MB-231 cells, respectively. CONCLUSION: This designed drug delivery system was more water-soluble and had enhanced in vitro characteristics and higher cytotoxic activity on cancer cells.

Peptide functionalized poly ethylene glycol-poly caprolactone nanomicelles for specific cabazitaxel delivery to metastatic breast cancer cells.

Metastatic cancer is responsible for 90% of deaths in world. Usage of nano-carriers improve the delivery and efficacy of chemotherapeutic agents. Recent studies suggest that decoration of the surface of nano-carriers with various targeting agents may further improve their overall therapeutic efficacy. Using specified peptides in targeted drug delivery is a key point in recent researches. In this study, tumor metastasis targeting (TMT) homing peptide was applied as a targeting group to improve specific drug delivery to tumor cells. TMT peptide is conjugated to poly ethylene glycol-poly caprolactone (PEG-PCL) micellar nanoparticles as carriers for targeted delivery of cabazitaxel to metastatic breast cancer cells. Synthesis of PEG-PCL copolymer was performed by amidation reaction between carboxylic acid group of PEG and amine group of PCL. Nanomicelles were prepared via solvent evaporation method. TMT peptide was covalently conjugated onto nanomicelles through the amine group of PEG. TMT-PEG-PCL nanoparticles were analyzed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), dynamic light scattering (DLS), gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR). Toxicity and cellular uptake of nanomicelles were investigated by in vitro cytotoxicity assays and confocal scanning microscopy in MCF-7 (non-metastatic breast cancer cells) and MDA-MB-231 (metastatic breast cancer cells). The final nanomicelles had about 110nm mean size and encapsulation efficiency of 82.5%. Treatment of metastatic breast cancer cells with targeted nanomicelles significantly increased the necrosis rate to 65%, compared to 33% in non-targeted nanomicelles and 8% in control group. The MDA-MB-231 cells treated with targeted nanomicelles exhibited a strong increase in the fluorescence intensity of coumarin in comparison to the cells treated with non-targeted nanomicelles (p<0.001). It could be concluded that the present carrier has the potential to be considered in treatment of metastatic breast cancer cells.

Preparation, Characterization and Evaluation of Drug Release Properties of Simvastatin-loaded PLGA Microspheres.

Microspheres formulated from poly (D, L-lactic-co-glycolide) (PLGA), a biodegradable polymer, have been extensively evaluated as a drug delivery system. In this study, the preparation, characterization and drug release properties of the PLGA microspheres were evaluated. Simvastatin (SIM)-loaded PLGA microspheres were prepared by oil-in-water emulsion/solvent evaporation method. The microspheres were then frozen to -80 °C, they were freeze dried for 24 h. Characterization of SIM-loaded PLGA microspheres was evaluated by X-ray diffraction analysis, Fourier transform infrared spectroscopy analysis, and scanning electron microscopy (SEM). Drug release potential was evaluated by UV-spectrophotometry. The experimental results revealed that SIM-loaded PLGA microspheres can be successfully obtained through solvent evaporation method with appropriate morphologic characteristics and high encapsulation efficiency. The drug release pattern from polymeric microspheres in the phosphate buffered saline medium was measured during a 21-day period using UV-spectrophotometry. The correlation coefficient value (r2= 0.9878) of the trend lines of the graph showed that the SIM-loaded PLGA microspheres best fit with zero order release pattern. No burst release was observed with polymeric matrix. The drug release characteristic of the microspheres ascertained that the release was about 27% for SIM-loaded microspheres, which occurred within the first 6 days after maintaining the microspheres in phosphate buffer saline. Also, the microspheres successfully presented a slow release and the duration of the release lasted for more than 21 days. It can be concluded that SIM-loaded PLGA microspheres hold great promise for using as a drug-delivery system in biomedical applications, especially in drug delivery systems and tissue engineering.

Enhanced Cytotoxicity to Cancer Cells by Codelivery and Controlled Release of Paclitaxel-loaded Sirolimus-conjugated Albumin Nanoparticles.

Recently, it is suggested that mTOR signaling pathway is an important mediator in many cancers especially breast cancer. Therefore, effects of sirolimus as a mTOR inhibitor in breast cancer have been studied in combination with paclitaxel with or without controlled release effect. In this work, we prepared a water-soluble formulation of sirolimus-conjugated albumin nanoparticles loaded with paclitaxel, to study the effects of sirolimus concentration when it releases more later than paclitaxel in comparison with sirolimus-paclitaxel-loaded albumin nanoparticles. Also effects of paclitaxel loading on cytotoxic properties of nanoparticles were studied. Sirolimus was succinylated at 42-OH with enzymatic reaction of Candida antarctica lipase B, and then its carboxylic group was activated with EDC/NHS and conjugated to the lysine residues of albumin. Paclitaxel was loaded on albumin surface by nab technique in concentration range of 0-10 µg/mL. Sirolimus-conjugated nanoparticles with 0.01 µg/mL paclitaxel showed lowest cell viability of 44% while it was 53% for non-conjugated nanoparticles in MDA-MB-468 cell lines after 48 h (p-value = 0.003). In MCF-7 cell lines, sirolimus-conjugated nanoparticles with 0.1 µg/mL paclitaxel showed lowest cell viability of 35.69% while it was 48% for non-conjugated nanoparticles after 48 h (p-value = 0.03). We guess that when cancer cell lines arrest in G2-M by anticancer drugs like paclitaxel, Akt activates mTOR to make cells continue living, then inhibiting mTOR can enhance anticancer effects.

Preparation and Characterization of Three Tilmicosin-loaded Lipid Nanoparticles: Physicochemical Properties and in-vitro Antibacterial Activities.

Tilmicosin (TLM) is an important antibiotic in veterinary medicine with low bioavailability and safety. This study aimed to formulate and evaluate physicochemical properties, storage stability after lyophilization, and antibacterial activity of three TLM-loaded lipid nanoparticles (TLM-LNPs) including solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), and lipid-core nanocapsules (LNCs). Physicochemical parameters such as particle size-mean diameter, polydispersity index, zeta potential, drug encapsulation efficiency (EE), loading capacity, and morphology of the formulations were evaluated and the effects of various cryoprotectants during lyophilization and storage for 8 weeks were also studied. The profiles of TLM release and the antibacterial activities of these TLM-LNPs suspensions (against Escherichia coli and Staphylococcus aureus) were tested in comparison with their corresponding powders. TLM-LNPs suspensions were in nano-scale range with mean diameters of 186.3 ± 1.5, 149.6 ± 3.0, and 85.0 ± 1.0nm, and also EE, 69.1, 86.3, and 94.3% for TLM- SLNs, TLM-NLCs, and TLM- LNCs respectively. TLM-LNCs gave the best results with significantly low particle size and high EE (p<0.05). Mannitol was the most effective cryoprotectant for lyophilization and storage of TLM-LNPs. The drug release profiles were biphasic and the release times were longer at pH 7.4 where TLM-NLCs and TLM-LNCs powders showed longer release times. In microbiological tests, S. aureus was about 4 times more sensitive than E. coli to TLM-LNPs with minimum inhibitory concentration ranges of 0.5-1.0 and 2-4 µg/mL respectively, and TLM-LNCs exhibited the best antibacterial activities. In conclusion, TLM-LNP formulations especially TLM-LNCs and TLM-NLCs are promising carriers for TLM with better drug encapsulation capacity, release behavior, and antibacterial activity.

Specific targeting delivery to MUC1 overexpressing tumors by albumin-chitosan nanoparticles conjugated to DNA aptamer.

Chitosan-coated human serum albumin nanoparticles were functionalized by MUC1 aptamer to obtain a selective drug carrier toward cancers overexpressing MUC1. The negative charges of albumin nanoparticles were shifted to positive charges by surface modification with chitosan, and MUC1 was conjugated through an acrylate spacer. The cytotoxicity of targeted nanoparticles was significantly more than non-aptamer nanoparticles, and also the chitosan-coated nanoparticles had more cytotoxic effects than the negatively charged albumin nanoparticles. The IC50 of targeted nanoparticles was 28 and 26% of free paclitaxel in MCF7 and T47D cells at 48h, respectively. Confocal laser scanning electron microscopy showed that aptamer conjugation and positive charge increase the cellular uptake. 66% of paclitaxel was released within 32h, but 100% of drug was released at pH=5.5 (similar cancer cells). The paclitaxel plasma amount was at a good level of 17.6% at 2h for increasing the chance of cellular uptake.

Paclitaxel molecularly imprinted polymer-PEG-folate nanoparticles for targeting anticancer delivery: Characterization and cellular cytotoxicity.

The aim of this work was to synthesize molecularly imprinted polymer-poly ethylene glycol-folic acid (MIP-PEG-FA) nanoparticles for use as a controlled release carrier for targeting delivery of paclitaxel (PTX) to cancer cells. MIP nanoparticles were synthesized by a mini-emulsion polymerization technique and then PEG-FA was conjugated to the surface of nanoparticles. Nanoparticles showed high drug loading and encapsulation efficiency, 15.6 ± 0.8 and 100%, respectively. The imprinting efficiency of MIPs was evaluated by binding experiments in human serum. Good selective binding and recognition were found in MIP nanoparticles. In vitro drug release studies showed that MIP-PEG-FA have a controlled release of PTX, because of the presence of imprinted sites in the polymeric structure, which makes it is suitable for sustained drug delivery. The drug release from polymeric nanoparticles was indeed higher at acidic pH. The molecular structure of MIP-PEG-FA was confirmed by Hydrogen-Nuclear Magnetic Resonance (H NMR), Fourier Transform InfraRed (FT-IR), and Attenuated Total Reflection (ATR) spectroscopy, and their thermal behaviors by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Scanning Electron Microscopy (SEM) and Photon Correlation Spectroscopy (PCS) results showed that nanoparticles have a smooth surface and spherical shape with an average size of 181 nm. MIP-PEG-FA nanoparticles showed a greater amount of intracellular uptake in folate receptor-positive cancer cells (MDA-MB-231 cells) in comparison with the non-folate nanoparticles and free PTX, with half maximal inhibitory concentrations (IC50) of 4.9 ± 0.9, 7.4 ± 0.5 and 32.8 ± 3.8 nM, respectively. These results suggest that MIP-PEG-FA nanoparticles could be a potentially useful drug carrier for targeting drug delivery to cancer cells.

Aptamer decorated hyaluronan/chitosan nanoparticles for targeted delivery of 5-fluorouracil to MUC1 overexpressing adenocarcinomas.

An aptamer (Apt) conjugated hyaluronan/chitosan nanoparticles (HACSNPs) were prepared as carrier for targeted delivery of 5-fluorouracil (5FU) to mucin1 (MUC1) overexpressing colorectal adenocarcinomas. Nanoparticles had about 181 nm size, encapsulation efficiency of 45.5 ± 2.8 and acceptable stability. Conjugation of MUC1-binding Apt to the surface of the nanoparticles was confirmed by gel electrophoresis. Toxicity and cellular uptake of nanoparticles were investigated by in vitro cytotoxicity assays and confocal scanning microscopy in (MUC1(+)) human adenocarcinoma and (MUC1(-)) Chinese hamster ovary cells. Toxicity of nanoparticles were significantly higher in comparison with free drug in both cell lines while this rising was more efficient for nanoparticles decorated with Apt in MUC1(+) cell line. The same result was observed in the cellular uptake study. It could be concluded that the present system has the potential to be considered in treatment of MUC1(+) colorectal adenocarcinomas.

Regulation of BAX/BCL2 gene expression in breast cancer cells by docetaxel-loaded human serum albumin nanoparticles.

Today, using nanoparticle-based drug delivery systems has expanded to avoid anticancer side effects. Taxanes are important chemotherapeutic agents in the treatment of metastatic breast cancer. In this study, docetaxel (DTX)-loaded human serum albumin (HSA) nanoparticles (NPs) were prepared and characterized. Drug toxicity of the nanoparticles was measured by MTT assay with different drug concentrations (0.01, 0.1, 0.5, 1 and 5 µM) at different incubation times (24, 48 and 72 h). Expression of BAX/BCL2 mRNA levels was determined by real-time PCR. The size of NPs prepared and used in our study was about 147 nm with surface charge of -29.6 mV. Results obtained from MTT assay showed that 0.5 µM of free drug had 50 % toxicity on MCF-7 cells after 48-h incubation. Real-time PCR results showed an increase in expression of BAX and no change for BCL2. In conclusion, a significant overexpression of BAX gene and changes in BAX/BCL2 ratio were observed for DTX-loaded HSA nanoparticles compared with free DTX and may provide a potential therapy to inhibit anticancer drug resistance.

Protein corona hampers targeting potential of MUC1 aptamer functionalized SN-38 core-shell nanoparticles.

Nanoparticles have been considered to improve delivery and physicochemical characteristics of bioactive agents in recent years. In this study, a core-shell chitosan nanoparticulate system was prepared for the targeted delivery of SN-38. SN-38, an active metabolite of camptothecin, conjugated to hyaluronic acid (HA) was used as the shell of chitosan nanoparticles decorated with MUC1 aptamer. The conjugation was confirmed by UV and (1)H NMR techniques. Targeting efficiency was evaluated by confocal microscopy and flow cytometry. It was shown that MUC1 decoration increased the uptake of nanoparticles by HT29 cells, MUC1 positive cell line, while CHO as MUC1 negative cell line showed no enhanced uptake of decorated nanoparticles. Compared to non-targeted nanoparticles, flow cytometric annexin V/PI analyses showed that the nanoparticles exert cytotoxicity through apoptosis. It was, however, shown that protein corona adsorption at the surface of nanoparticles hampered the cytotoxicity of nanoparticles, as there was no difference between the cytotoxicity of targeted and non-targeted nanoparticles, when treated with bovine serum albumin prior to cytotoxicity study.

Improved anticancer delivery of paclitaxel by albumin surface modification of PLGA nanoparticles.

BACKGROUND: Nanoparticles (NPs) play an important role in anticancer delivery systems. Surface modified NPs with hydrophilic polymers such as human serum albumin (HSA) have long half-life in the blood circulation system. METHODS: The method of modified nanoprecipitation was utilized for encapsulation of paclitaxel (PTX) in poly (lactic-co-glycolic acid) (PLGA). Para-maleimide benzoic hydrazide was conjugated to PLGA for the surface modifications of PLGA NPs, and then HSA was attached on the surface of prepared NPs by maleimide attachment to thiol groups (cysteines) of albumin. The application of HSA provides for the longer blood circulation of stealth NPs due to their escape from reticuloendothelial system (RES). Then the physicochemical properties of NPs like surface morphology, size, zeta potential, and in-vitro drug release were analyzed. RESULTS: The particle size of NPs ranged from 170 to 190 nm and increased about 20-30 nm after HSA conjugation. The zeta potential was about -6 mV and it decreased further after HSA conjugation. The HSA conjugation in prepared NPs was proved by Fourier transform infrared (FT-IR) spectroscopy, faster degradation of HSA in Differential scanning calorimetry (DSC) characterization, and other evidences such as the increasing in size and the decreasing in zeta potential. The PTX released in a biphasic mode for all colloidal suspensions. A sustained release profile for approximately 33 days was detected after a burst effect of the loaded drug. The in vitro cytotoxicity evaluation also indicated that the HSA NPs are more cytotoxic than plain NPs. CONCLUSIONS: HSA decoration of PLGA NPs may be a suitable method for longer blood circulation of NPs.