Novel self-assembled amphiphilic poly(epsilon-caprolactone)-grafted-poly(vinyl alcohol) nanoparticles: hydrophobic and hydrophilic drugs carrier nanoparticles

Environmentally Friendly Strategies for Formulating Vegetable Oil-Based Nanoparticles for Anticancer Medicine

The development of green synthesized polymeric nanoparticles with anticancer studies has been an emerging field in academia and the pharmaceutical and chemical industries. Vegetable oils are potential substitutes for petroleum derivatives, as they present a clean and environmentally friendly alternative and are available in abundance at relatively low prices. Biomass-derived chemicals can be converted into monomers with a unique structure, generating materials with new properties for the synthesis of sustainable monomers and polymers. The production of bio-based polymeric nanoparticles is a promising application of green chemistry for biomedical uses. There is an increasing demand for biocompatible and biodegradable materials for specific applications in the biomedical area, such as cancer therapy. This is encouraging scientists to work on research toward designing polymers with enhanced properties and clean processes, containing oncology active pharmaceutical ingredients (APIs). The nanoencapsulation of these APIs in bio-based polymeric nanoparticles can control the release of the substances, increase bioavailability, reduce problems of volatility and degradation, reduce side effects, and increase treatment efficiency. This review discusses the use of green chemistry for bio-based nanoparticle production and its application in anticancer medicine. The use of castor oil for the production of renewable monomers and polymers is proposed as an ideal candidate for such applications, as well as more suitable methods for the production of bio-based nanoparticles and some oncology APIs available for anticancer application.

Effect of Lipophilic Chains on the Antitumor Effect of a Dendritic Nano Drug Delivery System

Oligoethylene glycol dendron (G2) has been used in drug delivery due to its unique dendritic structure and excellent properties. In order to investigate the effects of lipophilic chains on drug delivery, the amphiphilic hybrid compound G2-C18 is synthesized, and celastrol (CSL) is selected to prepare "core-shell" structured CSL-G2-C18 nanoparticles (NPs) via the antisolvent precipitation method. Meanwhile, CSL-G2 NPs are prepared as the control. The two NPs show similar particle sizes and polydispersity indexes, while their morphologies exhibit dramatic differences. CSL-G2 NPs are solid spherical particles, while G2-C18 NPs are vesicles. The two NPs present ideal stability and similar release tendencies. The in vitro toxicity results show that the cell inhibition effect of CSL-loaded NPs is significantly enhanced when compared with free CSL, and the antitumor effect of CSL-G2-C18 NPs is stronger than that of CSL-G2 NPs. The IC₅₀ value of CSL-G2 NPs and CSL-G2-C18 NPs is enhanced about 2.8-fold and 5-fold when compared with free CSL, respectively. The above results show that lipophilic chain-linking dendritic hybrid nanocarriers promote antitumor activity by affecting the morphology of NPs, which may aid in the selection of carrier designs.

Olanzapine Loaded Nanostructured Lipid Carriers via High Shear Homogenization and Ultrasonication

The aim of this study was to understand the effect of high shear homogenization (HSH) and ultrasonication (US) on the physicochemical properties of blank and olanzapine loaded nanostructured lipid carriers (NLCs) along with their drug loading potential and drug release profiles from formulated particles. NLCs were prepared with different ratios of Compritol and Miglyol as the solid and liquid lipids, respectively, under changing HSH and US times between 0 to 15 min. The surfactants (Poloxamer 188 (P188) and tween 80) and the drug content was kept constant in all formulations. The prepared NLCs were evaluated for particle size, polydispersity index, zeta potential, drug crystallinity and chemical interactions between lipids and OLZ. The in-vitro drug release was performed using dialysis tube method in phosphate buffer solution (PBS) at pH 7.4. The formulated NLCs were negatively charged, spherically shaped and monodisperse, with particle sizes ranging from 112 to 191 nm. There was a significant influence of US time on the preparation of NLCs in comparison to HSH, where a significant reduction in the mean particle diameter was seen after 5 min of sonication. An increase of Miglyol content in NLCs led to an increase in particle size. In general, application of US led to decrease in particle size after HSH but an increase in particle diameter of low Miglyol containing preparation was also observed with longer sonication time. OLZ was successfully encapsulated in the NLCs and a total release of 89% was achieved in 24 h in PBS at pH 7.4.

Evaluation of the Hemocompatibility and Anticancer Potential of Poly(ε-Caprolactone) and Poly(3-Hydroxybutyrate) Microcarriers with Encapsulated Chrysin

In this work, novel chrysin-loaded poly(ε-caprolactone) and poly(3-hydroxybutyrate) microcarriers were synthesized according to a modified oil-in-water single emulsion/solvent evaporation method, utilizing poly(vinyl alcohol) surfactant as stabilizer and dispersing agent for the emulsification, and were evaluated for their physico-chemical and morphological properties, loading capacity and entrapment efficiency and in vitro release of their load. The findings suggest that the novel micro-formulations possess a spherical and relatively wrinkled structure with sizes ranging between 2.4 and 24.7 µm and a highly negative surface charge with z-potential values between (-18.1)-(-14.1) mV. The entrapment efficiency of chrysin in the poly(ε-caprolactone) and poly(3-hydroxybutyrate) microcarriers was estimated to be 58.10% and 43.63%, whereas the loading capacity was found to be 3.79% and 15.85%, respectively. The average release percentage of chrysin was estimated to be 23.10% and 18.01%, respectively. The novel micromaterials were further biologically evaluated for their hemolytic activity through hemocompatibility studies over a range of hematological parameters and cytoxicity against the epithelial human breast cancer cell line MDA-MB 231. The poly(ε-caprolactone) and poly(3-hydroxybutyrate) microcarriers reached an IC50 value with an encapsulated chrysin content of 149.19 µM and 312.18 µM, respectively, and showed sufficient blood compatibility displaying significantly low (up to 2%) hemolytic percentages at concentrations between 5 and 500 µg·mL-1.

Starch/PCL composite nanofibers by co-axial electrospinning technique for biomedical applications

BACKGROUND

In this study, starch and polycaprolactone (PCL), composite nanofibers were fabricated by co-axial needle electrospinning technique. Processing parameters such as polymer concentration, flow rate and voltage had a marked influence on the composite fiber diameter. Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), mechanical and physical properties (such as density, viscosity and electrical conductivity) of the composite fibres were evaluated. Moreover, a cell culture test was performed in order to determine their cytotoxicity for wound dressing application.

RESULTS

The effect of starch ratio in the solution on the properties and morphological structure of the fibers produced was presented. With lower starch concentration values, the fibers have greater ultimate tensile strength characteristic (mostly 4 and 5 wt%). According to SEM results, it can be figured out that the nanofibers fabricated have good spinnability and morphology. The mean diameter of the fibers is about 150 nm. According to results of cell culture study, the finding can be determined that the increase of starch in the fiber also increases the cell viability.

CONCLUSIONS

Composite nanofibers of starch/PCL have been prepared using a co-axial needle electrospinning technique. PCL was successfully encapsulated within starch. Fiber formation was observed for different ratio of starch. With several test, analysis and measurement performed, some important parameters such as quality and effectuality of each fiber obtained for wound dressing applications were discussed in detail.

SLM produced porous titanium implant improvements for enhanced vascularization and osteoblast seeding

To improve well-known titanium implants, pores can be used for increasing bone formation and close bone-implant interface. Selective Laser Melting (SLM) enables the production of any geometry and was used for implant production with 250-µm pore size. The used pore size supports vessel ingrowth, as bone formation is strongly dependent on fast vascularization. Additionally, proangiogenic factors promote implant vascularization. To functionalize the titanium with proangiogenic factors, polycaprolactone (PCL) coating can be used. The following proangiogenic factors were examined: vascular endothelial growth factor (VEGF), high mobility group box 1 (HMGB1) and chemokine (C-X-C motif) ligand 12 (CXCL12). As different surfaces lead to different cell reactions, titanium and PCL coating were compared. The growing into the porous titanium structure of primary osteoblasts was examined by cross sections. Primary osteoblasts seeded on the different surfaces were compared using Live Cell Imaging (LCI). Cross sections showed cells had proliferated, but not migrated after seven days. Although the cell count was lower on titanium PCL implants in LCI, the cell count and cell spreading area development showed promising results for titanium PCL implants. HMGB1 showed the highest migration capacity for stimulating the endothelial cell line. Future perspective would be the incorporation of HMGB1 into PCL polymer for the realization of a slow factor release.

Paclitaxel Nano-Delivery Systems: A Comprehensive Review

Paclitaxel is one of the most effective chemotherapeutic drugs ever developed and is active against a broad range of cancers, such as lung, ovarian, and breast cancers. Due to its low water solubility, paclitaxel is formulated in a mixture of Cremophor EL and dehydrated ethanol (50:50, v/v) a combination known as Taxol. However, Taxol has some severe side effects related to Cremophor EL and ethanol. Therefore, there is an urgent need for the development of alternative Taxol formulations. The encapsulation of paclitaxel in biodegradable and non-toxic nano-delivery systems can protect the drug from degradation during circulation and in-turn protect the body from toxic side effects of the drug thereby lowering its toxicity, increasing its circulation half-life, exhibiting improved pharmacokinetic profiles, and demonstrating better patient compliance. Also, nanoparticle-based delivery systems can take advantage of the enhanced permeability and retention (EPR) effect for passive tumor targeting, therefore, they are promising carriers to improve the therapeutic index and decrease the side effects of paclitaxel. To date, paclitaxel albumin-bound nanoparticles (Abraxane®) have been approved by the FDA for the treatment of metastatic breast cancer and non-small cell lung cancer (NSCLC). In addition, there are a number of novel paclitaxel nanoparticle formulations in clinical trials. In this comprehensive review, several types of developed paclitaxel nano-delivery systems will be covered and discussed, such as polymeric nanoparticles, lipid-based formulations, polymer conjugates, inorganic nanoparticles, carbon nanotubes, nanocrystals, and cyclodextrin nanoparticles.

Self-assembled polymeric nanoparticles based on oleic acid-grafted chitosan oligosaccharide: biocompatibility, protein adsorption and cellular uptake

Oleic acid-grafted chitosan oligosaccharide (OA-g-CSO) was synthesized to prepare self-assembled nanoparticles by sonication at physiological pH value (7.4). The nanoparticles appeared to be spherical in shape with a diameter of 158.1 ± 64.3 nm. The biocompatibility of OA-g-CSO nanoparticles was evaluated in vitro via MTT assay and hemolysis test. The nanoparticles showed no cytotoxicity to mouse embryo fibroblasts and the hemolysis rates came well within permissible limits (<2 %) in the tested conditions. When incubated with bovine calf serum, the protein adsorption on the surface of OA-g-CSO nanoparticles was concentration-dependent, and the amount of bovine serum albumin was in the highest proportion of the total amount of adsorbed proteins. Cellular uptake rate was evaluated by incubating fluorescence labeled OA-g-CSO nanoparticles with human lung carcinoma cells (A549). OA-g-CSO nanoparticles could be taken up by A549 cells, and the uptake rates increased with incubation time and particle concentration.

Surface-modified cobalt oxide nanoparticles: new opportunities for anti-cancer drug development

The development of smart nanoparticles that can exhibit the anti-cancer activity, introduces better efficacy and lower toxicity for treatment. The present study was aimed to evaluate the anti-cancer activity of surface functionalized CoO nanoparticles against Jurkat (T-cell lymphoma) and KB (oral carcinoma) cell lines. The nano-sized cobalt oxide nanoparticles (CoO) was prepared by thermal decomposition method followed by surface modification using phosphonomethyl iminodiacetic acid (PMIDA). The PMIDA-coated CoO nanoparticle was characterized by X-ray diffraction, dynamic light scattering, and transmission electron microscopy; and the conjugation was analyzed by Fourier transform infrared spectroscopy. The resultant nanoparticles with an average size less than 100 nm measured by dynamic light scattering and transmission electron microscopy. Cytotoxicity study, flow cytometric analysis and scanning electron micrographs have been revealed that PMIDA-coated nanoparticles significantly enhances the cellular uptake of the nanoparticle and thus facilitates apoptosis of cancer cell (Jurkat and KB). For the application of PMIDA-coated CoO nanoparticles in the medical field, doxorubicin, a potent anti-cancer drug, has been used in similar fashion in this experimental design and all these effects or patterns were observed.

Poly-є-caprolactone based formulations for drug delivery and tissue engineering: A review

Biodegradable polymer based novel drug delivery systems have provided many avenues to improve therapeutic efficacy and pharmacokinetic parameters of medicinal entities. Among synthetic biodegradable polymer, poly-є-caprolactone (PCL) is a polymer with very low glass transition temperature and melting point. Owing to its amicable nature and tailorable properties it has been trialed in almost all novel drug delivery systems and tissue engineering application in use/investigated so far. This review aims to provide an up to date of drugs incorporated in different PCL based formulations, their purpose and brief outcomes. Demonstrated PCL formulations with or without drugs, intended for drug delivery and/or tissue engineering application such as microsphere, nanoparticles, scaffolds, films, fibers, micelles etc. are categorized based on method of preparation.

Preparation and characterization of self-assembled nanoparticles based on folic acid modified carboxymethyl chitosan

Folate (FA) modified carboxymethyl chitosan (FCC) has been synthesized and the hydrogel nanoparticles can be prepared after the sonication. Formation and characteristics of nanoparticles of FCC were studied by fluorescence spectroscopy and dynamic light scattering methods. The critical aggregation concentration value of FCC in water was 9.34 × 10(-2) mg/ml and the mean hydrodynamic diameter of particle was 267.8 nm. The morphology of nanoparticles was observed by transmission electron microscopy which had spherical shape. Loading capacity (LC), loading efficiency (LE) and the in vitro release profiles of nanoparticles were investigated by doxorubicin (DOX) as a model drug. When the initially added amount of DOX versus the constant amount of FCC polymer was increased, the LC in the nanoparticles was gradually increased and the LE decreased. The in vitro release profile of the DOX from the FCC nanoparticles exhibited sustained release. Cellular uptake of FCC nanoparticles was found to be higher than that of nanoparticles based on linoleic acid (LA) modified carboxymethyl chitosan because of the FA-receptor-mediated endocytosis, thereby providing higher cytotoxicity against Hela cells.

Formulation of a novel oxybenzone-loaded nanostructured lipid carriers (NLCs)

The objective of the current study was to formulate oxybenzone into nanostructured lipid carriers (NLCs) to enhance its sunscreening efficacy and safety. NLCs of oxybenzone were prepared by the solvent diffusion method. A complete 2(3) factorial design was used for the evaluation of the prepared oxybenzone NLCs. The study design involves the investigation of the effect of three independent variables namely liquid lipid type (Miglyol 812 and oleic acid), liquid lipid concentration (15% and 30%), and oxybenzone concentration (5% and 10% with respect to total lipids) on the particle size (p.s.) , the entrapment efficiency (EE%) and the in vitro drug release after 8 h. The prepared NLCs were spherical in overall shape and were below 0.8 microm. Miglyol 812 and 30% liquid lipid were found to significantly decrease the p.s. and increase the EE% when compared to oleic acid and 15% liquid lipid. Increasing oxybenzone concentration increased significantly the p.s. but did not affect the EE%. NLCs prepared using Miglyol 812, 15% liquid lipid, and 10% oxybenzone showed slower drug release when compared to those prepared using oleic acid, 30% liquid lipid, and 5% oxybenzone, respectively. The candidate oxybenzone-loaded NLC dispersion was then formulated into gel. The incorporation of oxybenzone into NLCs greatly increased the in vitro sun protection factor and erythemal UVA protection factor of oxybenzone more than six- and eightfold, respectively, while providing the advantage of overcoming side effects of free oxybenzone as evidenced by very low irritation potential.

Development and in vitro characterization of paclitaxel and docetaxel loaded into hydrophobically derivatized hyperbranched polyglycerols

In this study we report the development and in vitro characterization of paclitaxel (PTX) and docetaxel (DTX) loaded into hydrophobically derivatized hyperbranched polyglycerols (HPGs). Several HPGs derivatized with hydrophobic groups (C(8/10) alkyl chains) (HPG-C(8/10)-OH) and/or methoxy polyethylene glycol (MePEG) chains (HPG-C(8/10)-MePEG) were synthesized. PTX or DTX were loaded into these polymers by a solvent evaporation method and the resulting nanoparticle formulations were characterized in terms of size, drug loading, stability, release profiles, cytotoxicity, and cellular uptake. PTX and DTX were found to be chemically unstable in unpurified HPGs and large fractions (∼80%) of the drugs were degraded during the preparation of the formulations. However, both PTX and DTX were found to be chemically stable in purified HPGs. HPGs possessed hydrodynamic radii of less than 10nm and incorporation of PTX or DTX did not affect their size. The release profiles for both PTX and DTX from HPG-C(8/10)-MePEG nanoparticles were characterized by a continuous controlled release with little or no burst phase of release. In vitro cytotoxicity evaluations of PTX and DTX formulations demonstrated a concentration-dependent inhibition of proliferation in KU7 cell line. Cellular uptake studies of rhodamine-labeled HPG (HPG-C(8/10)-MePEG(13)-TMRCA) showed that these nanoparticles were rapidly taken up into cells, and reside in the cytoplasm without entering the nuclear compartment and were highly biocompatible with the KU7 cells.

Electrospun titanium dioxide nanofibers containing hydroxyapatite and silver nanoparticles as future implant materials

In this study, a good combination consisting of electrospun titanium dioxide (TiO(2)) nanofibers incorporated with high purity hydroxyapatite (HAp) nanoparticles (NPs) and antimicrobial silver NPs is introduced for hard tissue engineering applications. The synthesized nanofibers were characterized by various state of art techniques like; SEM, XRD, TEM, TEM EDS and XPS analyses. SEM results confirmed well oriented nanofibers and good dispersion of HAp and silver NPs, respectively. XRD results demonstrated well crystalline feature of three components used for electrospinning. Silver NPs were having a diameter in range of 5-8 nm indicated by TEM analysis. Moreover, TEM EDS analysis demonstrated the presence of each component with good dispersion over TiO(2) nanofiber. The surface analyses of nanofibers were investigated by XPS which indicated the presence of silver NPs on the surfaces of nanofibers. The obtained nanofibers were checked for antimicrobial activity by using two model organisms E. coli and S. aureus. Subsequently, antimicrobial tests have indicated that the prepared nanofibers do possess high bactericidal effect. Accordingly, these results strongly recommend the use of obtained nanofiber mats as future implant materials.

Development of transferrin functionalized poly(ethylene glycol)/poly(lactic acid) amphiphilic block copolymeric micelles as a potential delivery system targeting brain glioma

The aim of present study is to conceive a biodegradable poly(ethylene glycol)-polylactide (PEG-PLA) copolymer nanoparticle which can be surface biofunctionalized with ligands via biotin-avidin interactions and used as a potential drug delivery carrier targeting to brain glioma in vivo. For this aim, a new method was employed to synthesize biotinylated PEG-PLA copolymers, i.e., esterification of PEG with biotinyl chloride followed by copolymerization of hetero-biotinylated PEG with lactide. PEG-PLA nanoparticles bearing biotin groups on surface were prepared by nanoprecipitation technique and the functional protein transferrin (Tf) were coupled to the nanoparticles by taking advantage of the strong biotin-avidin complex formation. The flow cytometer measurement demonstrated the targeting ability of the nanoparticles to tumor cells in vitro, and the fluorescence microscopy observation of brain sections from C6 glioma tumor-bearing rat model gave the intuitive proof that Tf functionalized PEG-PLA nanoparticles could penetrate into tumor in vivo.

Preparation and characterization of amphiphilic poly-N-vinylpyrrolidone nanoparticles containing indomethacin

Amphiphilic poly-N-vinylpyrrolidone derivatives (Amph-PVP) with different molecular weight of hydrophilic PVP fragment and one terminal hydrophobic n-alkyl fragment of different length were synthesized for preparation of nano-scaled particles in aqueous media. To estimate novel polymer efficiency and perspective as basis for drug delivery systems, the polymeric micelle-like particles were prepared by dialysis and solvent evaporation methods. Indomethacin was incorporated into hydrophobic inner core of these nanoparticles as a typical model drug. From the dynamic light-scattering measurements, the size of particles formed was less than 200 nm with narrow monodisperse size distribution and nanoparticles size slightly increased with the amount of indomethacin encapsulated into inner core of Amph-PVP particles. The critical aggregation concentration values for prepared polymer samples determined by fluorescence spectroscopy were in micromole range which is lower than it is for common low molecular weight surfactants. As the hydrophobic fragment of amphiphilic polymer increased, the critical aggregation concentration values decreased. An increase of polymer hydrophilic fragment molecular weight produced larger nanoaggregates. In vitro release experiments using indomethacin-loaded Amph-PVP nanoparticles exhibited the sustained release behavior without any burst effect for most polymer samples.