Nanoparticle formulation for intra-articular treatment of osteoarthritic joints

In this study, a model hydrophilic drug (porphyrin) was encapsulated within hydrophobic polylactic acid (PLA) nanoparticles (NPs) with different crystallinity and the relevant release behaviors were investigated. The crystalline modification was done using a modified nanoprecipitation method, where homo and stereocomplexed PLA NPs with different average diameters based on varying polymer concentrations and solvent/nonsolvent ratios (S/N) were prepared. Entrapment efficiency and drug release of sterocomplexed‐PLA NPs were compared with neat poly(l‐lactic acid) (PLLA) NPs. Furthermore, to get the more sustained release, porphyrin‐loaded NPs were immobilized within electrospun poly(d,l‐lactide‐co‐glycolide (PLGA) nanofibers (NFs). Outcomes revealed that solution concentration and solvent/nonsolvent ratio play significant roles in the formation of homo and stereocomplexed NPs. On the other hand, it was found that the formation of stereocrystals did not significantly affect the size and morphology of NPs compared with neat NPs. With regard to the entrapment efficiency and drug content, stereocomplexd‐PLA NPs behave relatively the same as neat PLLA NPs while the more sustained release was observed for stereocomplexed NPs. Also, it was observed that electrospinning of PLGA solution loaded by NPs led to the uniform distribution of NPs into PLGA fibers. Encapsulating the drug‐loaded NPs into nanofibers decreased the rate of drug release by 50% after 24 h, compared with direct loading of drug into PLGA NFs. We conclude that it is possible to tune the entrapment efficiency and modify the release rate of the drug by giving small changes in the process parameters without altering the physical properties of the original drug substance and polymer.

In this work, blank polylactic acid (PLA) nanoparticles with unstained surface were prepared by the nano-deposition method. On the basis of the preparation, the effect of surface modification on brain microvascular endothelial cells (BMECs) targeting was examined by in vivo experiments and fluorescence microscopy. The results showed that PLA nanoparticles are less toxic than PACA nanoparticles but their BMECs targeting is similar to PACA nanoparticles. The experiments suggest that drugs can be loaded onto the particles and become more stable through adsorption on the surface of PLA nanoparticles with high surface activity. The surface of PLA nanoparticles was obviously modified and the hydrophilicity was increased as well in the presence of non-ionic surfactants on PLA nanoparticles. As a targeting moiety, polysobate 80 (T-80) can facilitate BMECs targeting of PLA nanoparticles.

Comparison between Free and Encapsulated Form of Epicatechin in Liposomes and In Polymeric Nanoparticles Against the Paraquat-Induced Toxicity of NRK-52E Cells

The purpose of this study was to encapsulate neurotoxin-I (NT-I) within polylactic acid (PLA) nanoparticles (NPs) and to evaluate their transport into the brain after intranasal administration (i.n.) using a microdialysis sampling technique. NT-I-NPs (NT-I radiolabeled with sodium [(125)I]iodide) were prepared and characterized. Then, NT-I-NPs were administered i.n. or i.v. to rats and the radioactivities in the olfactory bulbs were monitored for up to 240 min. The nanoparticles prepared were spherical with a homogenous size distribution. The mean particle size, zeta potential and entrapment efficiency were -28.6+/-2.3 mV, 65 nm and 35.5+/-2.8%, respectively. The brain transport results showed that the time to reach the peak level (T(max)) of NT-I-NPs (i.n.) was 65 min, shorter than NT-I-NPs (i.v.) (95 min) or NT-I (i.v.) (145 min). The concentration at peak level (C(max)) and the total area under the concentration-time curves from zero to 4 h (AUC(0-4 h)) of each group followed the following order: NT-I-NPs (i.n.)>NT-I-NPs (i.v.)>NT-I (i.v.). The corresponding absolute bioavailabilities (Fabs) of NT-I-NPs (i.n.) were about 160%, 196% with NT-I-NPs (i.v.) and NT-I (i.v.) as reference preparations, respectively. The brain delivery of NT-I could be enhanced with PLA nanoparticles either through i.n. or i.v. administration. Furthermore, the enhancement was more significant for i.n. than for i.v. administration. Nanoparticles as carriers would be a potential way to improve the brain transport for centrally active peptides.

Polylactic acid (PLA), a biodegradable and biocompatible polymer produced from renewable resources, has been widely used as a nanoparticulate platform for antigen and drug delivery. Despite generally regarded as safe, its immunotoxicological profile, when used as a polymeric nanoparticle (NP), is not well-documented. Thus, this study intends to address this gap, by evaluating the toxicity of two different sized PLA NPs (PLAA NPs and PLAB NPs), produced by two nanoprecipitation methods and extensively characterized regarding their physicochemical properties in in vitro experimental conditions. After production, PLAA NPs mean diameter (187.9 ± 36.9 nm) was superior to PLAB NPs (109.1 ± 10.4 nm). Interestingly, when in RPMI medium, both presented similar mean size (around 100 nm) and neutral zeta potential, possibly explaining the similarity between their cytotoxicity profile in PBMCs. On the other hand, in DMEM medium, PLAA NPs presented smaller mean diameter (75.3 ± 9.8 nm) when compared to PLAB NPs (161.9 ± 8.2 nm), which may explain its higher toxicity in RAW 264.7. Likewise, PLAA NPs induced a higher dose-dependent ROS production. Irrespective of size differences, none of the PLA NPs presented an inflammatory potential (NO production) or a hemolytic activity in human blood. The results herein presented suggest the hypothesis, to be tested in the future, that PLA NPs presenting a smaller sized population possess increased cytotoxicity. Furthermore, this study emphasizes the importance of interpreting results based on adequate physicochemical characterization of nanoformulations in biological medium. As observed, small differences in size triggered by the dispersion in cell culture medium can have repercussions on toxicity, and if not correctly evaluated can lead to misinterpretations, and subsequent ambiguous conclusions.

Curcumin is a known naturally occurring anti-inflammatory agent derived from turmeric, and it is commonly used as a herbal food supplement. Here, in order to overcome the inherent hydrophobicity of curcumin (Cur), polylactic acid (PLA) nanoparticles (NPs) were synthesised using a solvent evaporation, and an oil-in-water emulsion method used to encapsulate curcumin. Polymeric NPs also offer the ability to control rate of drug release. The newly synthesised NPs were analysed using a scanning electron microscope (SEM), where results show the NPs range from 50 to 250 nm. NPs containing graded amounts of curcumin (0 %, 0.5 %, and 2 %) were added to cultures of NIH3T3 fibroblast cells for cytotoxicity evaluation using the Alamar Blue assay. Then, the curcumin NPs were incorporated into an alginate/gelatin solution, prior to crosslinking using a calcium chloride solution (200 nM). These hydrogels were then characterised with respect to their chemical, mechanical and rheological properties. Following hydrogel optimization, hydrogels loaded with NP containing 2 % curcumin were selected as a candidate as a bioink for three-dimensional (3D) printing. The biological assessment for these bioinks/hydrogels were conducted using THP-1 cells, a human monocytic cell line. Cell viability and immunomodulation were evaluated using lactate dehydrogenase (LHD) and a tumour necrosis factor alpha (TNF-α) enzyme-linked immunosorbent (ELISA) assay, respectively. Results show that the hydrogels were cytocompatible and supressed the production of TNF-α. These bioactive hydrogels are printable, supress immune cell activation and inflammation showing immense potential for the fabrication of tissue engineering constructs.

Peptide loaded polymeric nanoparticles by non-aqueous nanoprecipitation

Activation of mucosal immunity is a key milestone for next-generation vaccine development. Biocompatible polymer-based nanoparticles (NPs) are promising vectors and adjuvants for mucosal vaccination. However, their in vivo uptake by mucosae and their biodistribution in antigen-presenting cells (APCs) need to be better understood to optimize mucosal nanovaccine designs. Here, we assessed if APCs are efficiently targeted in a spontaneous manner by surfactant-free poly(lactic acid) nanoparticles (PLA-NPs) after mucosal administration. Combining histology and flow imaging approaches, we describe and quantify the mucosal uptake of 200 nm PLA-NPs in adult zebrafish. Following bath administration, PLA-NPs penetrated and crossed epithelial barriers from all exposed mucosae. In mucosae, PLA-NPs accumulated in APCs, which were identified as dendritic cells (DCs), macrophages, and IgZ+ B cells in gills and skin. PLA-NP uptake by phagocytes was specific to these cell types, as PLA-NPs were not detected in neutrophils. Importantly, quantitative analyses in gills revealed that DCs take up PLA-NPs with specifically high efficiency. This study shows that surfactant-free PLA-NPs, which display optimal biocompatibility, can spontaneously target DCs with high efficiency in vivo following mucosal administration, and highlights PLA-NPs as powerful platforms for mucosal vaccine delivery in the medical and veterinary fields, and particularly in aquaculture.

Micrometer-sized double emulsions and antibubbles were produced and stabilized via the Pickering mechanism by colloidal interfacial layers of polymeric nanoparticles (NPs). Two types of nanoparticles, consisting either of polylactic acid (PLA) or polylactic-co-glycolic acid (PLGA), were synthesized by the antisolvent technique without requiring any surfactant. PLA nanoparticles were able to stabilize water-in-oil (W/O) emulsions only after tuning the hydrophobicity by means of a thermal treatment. A water-in-oil-in-water (W/O/W) emulsion was realized by emulsifying the previous W/O emulsion in a continuous water phase containing hydrophilic PLGA nanoparticles. Both inner and outer water phases contained a sugar capable of forming a glassy phase, while the oil was crystallizable upon freezing. Freeze drying the double emulsion allowed removing the oil and water and replacing them with air without losing the three-dimensional (3D) structure of the original emulsion owing to the sugar glassy phase. Reconstitution of the freeze-dried double emulsion in water yielded a dispersion of antibubbles, i.e., micrometric bubbles containing aqueous droplets, with the interfaces of the antibubbles being stabilized by a layer of adsorbed polymeric nanoparticles. Remarkably, it was possible to achieve controlled release of a flourescent probe (calcein) from the antibubbles through heating to 37 °C leading to bursting of the antibubbles.

Objectives: The purpose of the current examination was to establish a polymeric nanoparticle (NP) to supply Ansamycin to the central nervous system by improving blood–brain barrier permeability for bacterial meningitis, by emulsification solvent diffusion technique with numerous hydrophilic carriers. Materials and Methods: The polymeric NPs were prepared by emulsification solvent diffusion technique making use of Polylactic acid (PLA) as well as Polycaprolactone (PCL). Physical mixtures of drug with above-mentioned polymers were likewise prepared. The formulations were examined for Fourier-transform infrared spectroscopy and as well as differential scanning calorimetry (DSC), particle size, and also in vitro dissolution. Similarity factor (f2) was determined for the comparison between dissolution of pure drug and also drug polymer physical mixtures with NPs. Results: Phase solubility researches showed linear increase in the drug solubility with rise in carrier concentration. In vitro release studies disclosed that dissolution quality of Ansamycin was not satisfactory with PLA and also PCL for the release quality of the Ansamycin from the formulation. Nanoformulation of Ansamycin with PLA and also PCL displayed inadequaterate and extent of dissolution. Optimized batches of nano formulations of both the carriers were identified by the Fourier-transform infrared spectroscopy and also DSC evaluation, which suggested existence of interactions between ansamycin and carriers. Conclusions: PLA as well as PCL are not the appropriate polymers to serve as a carrier to deliver Ansamcyin.

To investigate a nuclear factor-kappa B decoy oligonucleotides strategy on the inhibition of tissue factor (TF) expression in cultured rat brain microvascular endothelial cells (BMECs) by polylactic acid (PLA) nanoparticles delivery system and to evaluate this new vector for in vitro gene therapy. Nanoparticles were formulated using poly D,L-polylactic acid with surface modifying by polysorbates 80. 3-[4,5-Dimethylthiazol-2,5-diphenyl-2H-tetrazolium bromide] (MTT) assays showed that PLA nanoparticles were not toxic to the cultured BMECs.The decoy oligonuceotides (ODNs) loaded within nanoparticles was 6 μg/mg, encapsulation efficacy was (60.5±1.5)%. It was observed by flow cytometry that the cellular uptake of nanoparticles depended on the time of incubation and the concentration of nanoparticles in the medium. And confocal microscopy demonstrated that nanoparticles localized mostly in the BMECs cytoplasm. The released decoy oligonuceotides (ODNs) uptaked by BMECs retained their biologic activity and led to reduced level of tissue factor expression as compared to control cultures. These findings offer a potential therapeutic strategy in the control of TF expression in BMECs in vitro and suggest that PLA nanoparticles may be appropriate as delivery vehicles for decoy strategy in the gene therapy of cerebral thrombosis.

Synthesis, characterization and evaluation of novel triblock copolymer based nanoparticles for vaccine delivery against hepatitis B

Drug resistance is still a bottle-neck hindering successful chemotherapy in leukemia treatment. Nanocarriers have emerged as promising candidates to circumvent drug resistance and discover potent drug combinations. Here, we showed that co-encapsulation of daunorubicin (DNR) and glycyrrhizic acid (GA) in polylactic acid (PLA) nanoparticles effectively bypassed drug resistance and remarkably inhibited the growth of drug-resistant leukemia cells. The quantification of intracellular drug found that the encapsulation effectively increased drug uptake in the resistant K562/A02 cells. Modification of P-glycoprotein antibody on nanoparticles further enhanced drug accumulation in the leukemia cells, which was also confirmed by fluorescent microscopy imaging. More importantly, loaded in PLA nanoparticles, DNR and GA exerted an excellent synergistic effect, leading to significantly improved cell inhibition compared to the treatments without nanocarriers and those with a single drug. Correlative mechanism study revealed that the drug delivery system drastically enhanced cell apoptosis by regulating apoptotic genes but did not influence MDR1 expression. The present study proposes a versatile strategy to improve the therapeutic efficacy against drug-resistant leukemia and inspires the discovery of more potent drug combinations for enhanced leukemia therapy.

RBD decorated PLA nanoparticle admixture with aluminum hydroxide elicit robust and long lasting immune response against SARS-CoV-2

Hyaluronans in the treatment of osteoarthritis of the knee: evidence for disease-modifying activity