Types Of Polymeric Nanoparticles Research Articles

Levofloxacin loaded chitosan and poly-lactic-co-glycolic acid nano-particles against resistant bacteria: Synthesis, characterization and antibacterial activity

BackgroundWith the global increase in antibacterial resistance, the challenge faced by developing countries is to utilize the available antibiotics, alone or in combination, against resistant bacterial strains. We aimed to encapsulate the levofloxacin (LVX) into polymeric nanoparticles using biodegradable polymers i.e. Chitosan and PLGA, estimating their physicochemical characteristics followed by functional assessment as nanocarriers of levofloxacin against the different resistant strains of bacteria isolated from biological samples collected from tertiary care hospital in Lahore, Pakistan. MethodsLVX-NPs were synthesized using ion gelation and double emulsion solvent-evaporation method employing chitosan (CS) and poly-lactic-co-glycolic acid (PLGA), characterized via FTIR, XRD, SEM, and invitro drug release studies, while antibacterial activity was assessed using Kirby-Bauer disc-diffusion method. ResultsData revealed that the levofloxacin-loaded chitosan nanoparticles showed entrapment efficiency of 57.14% ± 0.03 (CS-I), 77.30% ± 0.08(CS-II) and 87.47% ± 0.08 (CS-III). The drug content, particle size, and polydispersity index of CS-I were 52.22% ± 0.2, 559 nm ± 31 nm, and 0.030, respectively, whereas it was 66.86% ± 0.17, 595 nm ± 52.3 nm and 0.057, respectively for CS-II and 82.65% ± 0.36, 758 nm ± 24 nm and 0.1, respectively for CS-III. The PLGA-levofloxacin nanoparticles showed an entrapment efficiency of 42.80% ± 0.4 (PLGA I) and 23.80% ± 0.4 (PLGA II). The drug content, particle size and polydispersity index of PLGA-I were 86% ± 0.21, 92 nm ± 10 nm, and 0.058, respectively, whereas it was 52.41% ± 0.45, 313 nm ± 32 nm and 0.076, respectively for PLGA-II. The XRD patterns of both polymeric nanoparticles showed an amorphous nature. SEM analysis reflects the circular-shaped agglomerated nanoparticles with PLGA polymer and dense spherical nanoparticles with chitosan polymer. The in-vitro release profile of PLGA-I nanoparticles showed a sustained release of 82% in 120 h and it was 58.40% for CS-III. Both types of polymeric nanoparticles were found to be stable for up to 6 months without losing any major drug content. Among the selected formulations, CS-III and PLGA-I, CS-III had better antibacterial potency against gram+ve and gram-ve bacteria, except for K. pneumonia, yet, PLGA-I demonstrated efficacy against K. pneumonia as per CSLI guidelines. All formulations did not exhibit any signs of hemotoxicity, nonetheless, the CS-NPs tend to bind on the surface of RBCs. ConclusionThese data suggested that available antibiotics can effectively be utilized as nano-antibiotics against resistant bacterial strains, causing severe infections, for improved antibiotic sensitivity without compromising patient safety.

Elongational-flow elaboration of blend- and Janus-type polymeric nanoparticles

Anisotropic particles, in shape or chemistry, have raised enthusiasm since they interact with their surrounding in unique ways, leading to complex assemblies that can be used in applications ranging from energy to health. In this study, two different types of polymeric nanoparticles, blend-type with two hydrophobic polymers and Janus type with hydrophobic and hydrophilic parts were produced thanks to an emulsification elongational-flow microprocess. Particles with controlled sizes and size distribution were successfully produced in one step and the effect of material (e.g. polymers’ composition and concentration, solvent) and process (e.g. flow rates, emulsification time) parameters on nanoparticles’ characteristics were thoroughly studied. Particles’ diameter ranged from 90 to 200 nm, depending on the aforementioned parameters.

Nanocargos designed with synthetic and natural polymers for ovarian cancer management.

Ovarian cancer cells usually spread in the peritoneal region, and if chemotherapeutic drugs can be given in these regions with proximity, then the anticancer property of the chemotherapeutic drugs can enhance. However, chemotherapeutic drug administrations are hindered by local toxicity. In the drug delivery system, microparticles or nanoparticles are administered in a controlled manner. Microparticles stay in a close vicinity while nanoparticles are smaller and can move evenly in the peritoneum. Intravenous administration of the drug evenly distributes the medicine in the target places and if the composition of the drug has nanoparticles it will have more specificity and will have easy access to the cancer cells and tumors. Among the different types of nanoparticles, polymeric nanoparticles were proven as most efficient in drug delivery. Polymeric nanoparticles are seen to be combined with many other molecules like metals, non-metals, lipids, and proteins, which helps in the increase of cellular uptake. The efficiency of different types of polymeric nanoparticles used in delivering the load for management of ovarian cancer will be discussed in this mini-review.

PLGA Nanoparticles Uptake in Stem Cells from Human Exfoliated Deciduous Teeth and Oral Keratinocyte Stem Cells.

Polymeric nanoparticles have been introduced as a delivery vehicle for active compounds in a broad range of medical applications due to their biocompatibility, stability, controlled release of active compounds, and reduced toxicity. The oral route is the most used approach for delivery of biologics to the body. The homeostasis and function of oral cavity tissues are dependent on the activity of stem cells. The present work focuses, for the first time, on the interaction between two types of polymeric nanoparticles, poly (lactic-co-glycolic acid) or PLGA and PLGA/chitosan, and two stem cell populations, oral keratinocyte stem cells (OKSCs) and stem cells from human exfoliated deciduous teeth (SHEDs). The main results show that statistical significance was observed in OKSCs uptake when compared with normal keratinocytes and transit amplifying cells after 24 h of incubation with 5 and 10 µg/mL PLGA/chitosan. The CD117+ SHED subpopulation incorporated more PLGA/chitosan nanoparticles than nonseparated SHED. The uptake for PLGA/chitosan particles was better than for PLGA particles with longer incubation times, yielding better results in both cell types. The present results demonstrate that nanoparticle uptake depends on stem cell type, incubation time, particle concentration, and surface properties.

Antitumoral Drug-Loaded Biocompatible Polymeric Nanoparticles Obtained by Non-Aqueous Emulsion Polymerization.

Non-aqueous dispersions (NAD) with two types of polymeric nanoparticles (NPs), such as hydrophobic poly(ε-caprolactone) (PCL) and hydrophilic cross-linked poly(vinylpyrrolidone) (PNVP), were synthesized in the present study starting from monomer-in-silicone oil (PDMS) polymerizable non-aqueous emulsions stabilized with the same tailor-made PDMS-based block copolymer. These NPs were loaded with CCisplatin, an antitumoral model drug, directly from the emulsion polymerization step, and it was observed that the presence of the drug leads only to a slight increase of the NPs size, from 120 to 150 nm. The drug release kinetics was evaluated at 37 °C in phosphate buffer at pH = 7.4 and it appeared that the drug release rate from the hydrophilic cross-linked PNVP-based NPs is higher than that from the hydrophobic PCL-based NPs. Moreover, haemolysis tests revealed the fact that these two types of NPs have a good compatibility with the blood. Furthermore, for both the free and drug-loaded NPs, the in vitro cytotoxicity and apoptosis was studied on two types of cancer cell lines, such as MCF-7 (breast cancer cell line) and A-375 (skin cancer cell line). Both types of NPs had no cytotoxic effect but, at a concentration of 500 μg/mL, presented an apoptotic effect similar to that of the free drug.

Effect of Selected Comonomers on the Transition Temperature of Thermosensitive NIPA Derivatives Synthesized with an Anionic Initiator.

The present study evaluates the effect of the cationic initiator on the hydrodynamic diameter of copolymers of N-isopropylacrylamide nanogels synthesized via a surfactant-free precipitation polymerization at 70 °C in the presence of the cationic initiator 2,2'-azobis[2- methylpropionamidine] dihydrochloride. Three types of polymeric nanoparticles were synthesized using N, N'-methylenebisacrylamide as a crosslinker. The first batch was used as a reference. The second type of particles included a poly(ethylene glycol) methyl ether-acrylate monomer, while the third type used an N-tert-butylacrylamide comonomer. The hydrodynamic diameters of the synthesized particles were between 160 and 970 nm at 18 °C. The chemical composition and morphology of the synthesized co-polymeric nanoparticles were confirmed using infrared spectroscopy, nuclear magnetic resonance and scanning electron microscopy. The zeta potentials measured via dynamic light scattering were 20.0, 17.0, -0.1 mV for the three types, respectively. The volume phase transition temperature was between 22 and 41 °C. The polydispersity index of particles synthesized with N-tert-butylacrylamide varied depending on the measurement temperature.

Imaging of intracellular behavior of polymeric nanoparticles in Staphylococcus epidermidis biofilms by slit-scanning confocal Raman microscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy

In drug delivery systems employing polymeric nanoparticles, accurate delivery of drugs to target sites such as bacterial cells, cell tissues, and organelles is essential. In particular, when designing drug delivery systems for the treatment of the biofilm infections, evaluation of the interaction between polymeric nanoparticles and biofilm or bacterial cells using a simple technique is of significant importance. Here we develop two types of novel techniques for the biological imaging of the intracellular behavior of two types of polymeric nanoparticles, biodegradable chitosan-modified poly (dl-lactide-co-glycolide) (PLGA) nanoparticles and chitosan-modified polyvinyl caprolactam - polyvinyl acetate -polyethylene glycol graft copolymer (Soluplus®, Sol) nanoparticles, within a Staphylococcus epidermidis biofilm. As the first technique, Raman imaging of unstained biological materials using slit-scanning confocal Raman microscopy (unstained Raman imaging) was performed, and as the second, field-emission scanning electron microscopy with energy-dispersive X-ray spectroscopy analysis of biological materials labeled with quantum dots (SEM-QD imaging) was demonstrated. These analyses revealed differing localization of the respective nanoparticles within the biofilm in accordance with the specific interactions of PLGA nanoparticles and Sol nanoparticles with the biofilm. These novel techniques open the door to biological imaging and analyses with high spatial resolution, which will help to understand the efficacy of drug delivery to target materials.

Surface functionalization affects the zeta potential, coronal stability and membranolytic activity of polymeric nanoparticles

Nano materials are commonly functionalized to boost their physicochemical properties. However, there is little known about the impact of these modifications on cellular systems. Herein, we synthesized eight types of polymeric nanoparticles (NPs) bearing different functional groups, and investigated their effects on interactions with cellular membranes. As models for particle membrane interactions, hemolysis assays using human red blood cells and culture with A549 cells were utilized. Under protein-free conditions, the NPs showed a wide distribution of zeta potentials (ζPs) which showed a good correlation with their hemolytic potential. However, in the presence of serum or lung lining fluid, the ζPs of all NPs coalesced towards a single common negative value and showed neither hemolytic activity nor cytotoxicity to A549 cells. Lipase and protease treatment of the coronated particles did not restore their reactivity. These result simply proves that particle functionalization influences the stability of the particle corona which, if intact, prevents hemolytic activity and membrane disrupture.

Synthesis of polymeric and hybrid nanoparticles for electroplating applications

Monodisperse polymeric particles with diameters in the range of 60–1400 nm were prepared by (emulsifier-free) emulsion polymerization and incorporated into electrolytic zinc coatings aiming to improve the corrosion resistance of electrogalvanized steel. Various types of polymeric nanoparticles were thus synthesized in order to assess the effect of the emulsifier, initiator and comonomer type on the particle morphology, stability and codeposition behavior. The polymerization experiments were carried out in laboratory-scale glass reactors and the most promising recipes were successfully scaled-up in a fully automated pilot-scale reactor. Replicates of some representative experiments, which were run both in lab and pilot-scale reactors, indicated excellent reproducibility of the polymerization process. Uniform, polymer-containing zinc coatings were produced by electrolytic codeposition of the nanoparticles from an acid zinc plating bath using a rotating disk electrode (RDE). Hybrid polystyrene/silica nanoparticles with increased silica content were also prepared via emulsifier-free emulsion polymerization, in the presence of an ultrafine aqueous silica sol, to be used in electrocoating applications. The effect of key process parameters, such as initial monomers molar ratio and pH on the size, morphology and silica content of the produced hybrid nanoparticles was investigated.