PLA Nanoparticles Research Articles

Optimized Synthesis of Poly(Lactic Acid) Nanoparticles for the Encapsulation of Flutamide.

Biopolymeric nanoparticles (NPs) have gained significant attention in several areas as an alternative to synthetic polymeric NPs due to growing environmental and immunological concerns. Among the most promising biopolymers is poly(lactic acid) (PLA), with a reported high degree of biocompatibility and biodegradability. In this work, PLA NPs were synthesized according to a controlled gelation process using a combination of single-emulsion and nanoprecipitation methods. This study evaluated the influence of several experimental parameters for accurate control of the PLA NPs' size distribution and aggregation. Tip sonication (as the stirring method), a PLA concentration of 10 mg/mL, a PVA concentration of 2.5 mg/mL, and low-molecular-weight PLA (Mw = 5000) were established as the best experimental conditions to obtain monodisperse PLA NPs. After gelification process optimization, flutamide (FLU) was used as a model drug to evaluate the encapsulation capability of the PLA NPs. The results showed an encapsulation efficiency of 44% for this cytostatic compound. Furthermore, preliminary cell viability tests showed that the FLU@PLA NPs allowed cell viabilities above 90% up to a concentration of 20 mg/L. The comprehensive findings showcase that the PLA NPs fabricated using this straightforward gelification method hold promise for encapsulating cytostatic compounds, offering a novel avenue for precise drug delivery in cancer therapy.

Functionalized hydroxypropyl‐β‐cyclodextrin derivative as a versatile nanovehicle for delivery of paclitaxel

AbstractTo improve the therapeutic efficiency of paclitaxel (PTX) and reduce its toxicity to normal tissues, a novel hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) derivative has been designed and developed. The polymer (bio‐HP‐β‐CD(NAC)‐PLA) is synthesized by modifying HP‐β‐CD with polylactic acid, cysteine, and biotin. Using bio‐HP‐β‐CD(NAC)‐PLA as the carrier, a PTX‐loaded nanoparticulate system is developed by a modified emulsion solvent evaporation method. The optimized drug‐loaded nanoparticles are obtained with a mean diameter of 162.4 nm and drug loading of 16.1%. In vitro drug release study exhibits that PTX is released in a redox‐dependent manner. Cellular uptake study suggests that the bio‐HP‐β‐CD(NAC)‐PLA nanoparticles can be specifically taken up by MCF‐7 cells via the biotin receptor‐mediated endocytosis. In vitro and in vivo anticancer efficacy evaluations demonstrate the superior antitumor activity and negligible toxicity of the PTX‐loaded nanoparticles. It can be concluded that the proposed polymer bio‐HP‐β‐CD(NAC)‐PLA offers a promising drug delivery system for targeted delivery and controlled release of PTX.

Active Low-Density Polyethylene-Based Films by Incorporating α-Tocopherol in the Free State and Loaded in PLA Nanoparticles: A Comparative Study

In this work, alpha-tocopherol (α-TOC) was encapsulated in poly(lactic acid) nanoparticles (PLA NPs) and added to low-density polyethylene (LDPE) films with the aim of producing an active film for food packaging applications. PLA NPs loaded with α-TOC were produced through nanoprecipitation and dried using two methods (freeze-dryer and oven). LDPE-based films with final polymeric matrix concentrations of 10 and 20 g/kg were then produced through blow extrusion. The results showed that LDPE-based films loaded with α-TOC can be produced using blow extrusion, and a good distribution of PLA NPs can be obtained within the LDPE matrix as observed using scanning electron microscopy (SEM). The mechanical properties were affected by the incorporation of α-TOC and PLA NPs loaded with α-TOC, with the observation of a decrease in tensile strength and Young’s Modulus values and an increase in elongation at break. Regarding water vapor permeability, the films showed a reduction in the values with the addition of α-TOC and PLA NPs loaded with α-TOC compared to the LDPE film (control). Films with α-TOC in the free state and loaded in PLA NPs showed antioxidant activity, but their behavior was affected by the encapsulation process.

Abstract A031: Development of poly lactic acid based biodegradable nanoparticles for co-delivery of pirarubicin and gemcitabine for synergistic anti-tumor efficacy

Abstract Nanoparticles based drug delivery systems have provided a befitted solution for the poor pharmacokinetic properties and systemic toxicity caused by the chemo drugs because of their ability to improve bioavailability of the drugs at the desired site and thereby decreasing extracellular toxicity. The present work investigates the single or dual chemo drugs loaded PLA-based biodegradable polymeric nanoparticles for improved anti-tumor efficacy as compared to free drug formulations. For the study, an amphiphilic block copolymer; mPEG PLA has been synthesized and characterized using Gel permeation chromatography (GPC) for its molecular weight and poly dispersity index as well as with Nuclear magnetic resonance (NMR) and Fourier-transform Infrared (FT-IR) spectroscopies. Thereafter, two different chemo drugs Pirarubicin (PIRA, THP analogue of Doxorubicin) and Gemcitabine (GEM) have been chemically conjugated individually to mPEG PLA block copolymer via a linker molecule, Levulinic acid to give an acid labile polymer-drug conjugate and the % drug conjugation efficiency has been calculated using High performance liquid chromatography (HPLC). The synthesized polymer-drug conjugates have been employed to prepare PIRA/GEM single or dual-loaded nanoparticles via nanoprecipitation technique and the physiochemical properties including size, zeta potential, and stability were analyzed using Dynamic Light Scattering (DLS) and High-resolution transmission electron microscopy (HR-TEM). To carry out toxicity assessment of the mPEG PLA nanoparticles, both cytocompatibility and hemocompatibility were checked using MTT assay and Hemolysis assay respectively. Moreover, the cellular internalization studies of dye-loaded mPEG PLA nanoparticles were done using Confocal microscopy on SUM-149, breast cancer cells. Besides, the drug release kinetic studies of the free PIRA/GEM from the PIRA/GEM single or dual-loaded nanoparticles were carried out in different pH environments; pH 7.4 and pH 5.0. The in-vitro cell proliferation inhibition studies of PIRA/GEM or dual-loaded nanoparticles were carried out on different human and murine breast cancer cell lines including MCF-7, MDA-MB-468, SUM 149, MDA-MB-231 and 4T1 and half-maximal inhibitory concentrations (IC50 values) were compared to that of respective free drug formulations. The overall results suggested that the prepared sub-nano sized PIRA/GEM single or dual-loaded particles are highly stable, uniformly spherical in size and biocompatible in nature. They were found to possess high cellular uptake, sustained drug release rate and synergistic efficacy and potential against both human and murine breast cancer cells in-vitro conditions. Citation Format: Priya Gupta. Development of poly lactic acid based biodegradable nanoparticles for co-delivery of pirarubicin and gemcitabine for synergistic anti-tumor efficacy [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A031.

Bilayer nonwovens using natural rubber, poly(lactic acid) and bactericidal nanoparticles for wound dressings

Wound healing poses a significant challenge in healthcare, impacting not only on patients' quality of life but also placing a substantial financial burden on healthcare systems. Bilayer nonwovens have emerged as a promising solution for wound dressings due to their porous morphology, providing a high surface area for cellular adhesion and growth, and their permeability, allowing proper oxygen and fluid exchange to promote wound healing. When bactericide materials are added to the formulation, they can decrease or prevent infection caused by microorganisms, further aiding the healing process. Solution blow spinning is an appealing technique for creating bilayer nonwovens as it can produce high yields at a low cost. Yet, even though natural rubber boasts a well-established safety record in biomaterials, it remains an underexplored candidate for generating micro-nanofibrous structures. In this study, solution blow spinning was employed to fabricate bilayer composite nonwovens for wound dressing materials. The material architecture consisted of a bottom layer composed of a blend of natural rubber, poly(lactic acid) (PLA), and polyethylene glycol in the respective proportion of 2:1:3 w/w and a top layer composed of PLA and ZnO nanoparticles added in concentrations of 1%, 2.5%, and 5% based on the PLA mass of this layer. The top layer was further functionalized with Ag nanoparticles through spraying. The obtained materials demonstrated satisfactory hydrophobicity for cellular adhesion in the bottom layer, ranging from 51.95° to 92.20° of water sessile drop contact angle, and tunable mechanical strength, which could be controlled by varying the content of ZnO nanoparticles. Additionally, the material showed antimicrobial properties due to the presence of added Ag nanoparticles, able to inhibit E. coli, S. enterica serovar Typhimurium, and S. aureus by direct contact. Besides, the nonwoven prevented the passage of microorganisms due to the pore size of the structure. Overall, the unique properties of the developed material, such as its low cost, ease of production, and remarkable wound-healing properties, make it a promising candidate for wound dressing applications.

In vitro and in vivo evaluation of immune response of poly(lactic acid) nanoparticles with different end groups

Poly(lactic acid) (PLA) has excellent properties of biodegradability and biocompatibility, which is a US Food and Drug Administration (FDA) approved biopolymer for the preparation of safe and effective vaccines, drugs, and gene delivery systems. However, there still exists a great problem whether and how the end group affects the immune response of PLA vaccines. Therefore, the aim of this study was to evaluate the in vitro and in vivo of immune response of PLA nanoparticles (NPs) with carboxyl (COOH) and ester (COOR) end groups. In vitro experiments suggested COOH NPs could promote the higher phagocytosis and activation of bone marrow dendritic cells (BMDCs) with a lower cytotoxicity. In vivo experiments showed that COOR NPs and COOH NPs could strongly elicit IgG, IgG1, and IgG2a responses both in the short and long-terms. However, the highest T cell and B cell activation, and central memory T cells response was induced by COOH NPs. In addition, the COOH NPs could significantly enhance splenocytes proliferation and cytokines secretion. Thus, the PLA with the COOH end group shows greater potential as efficient carrier materials of NPs for enhancing cellular and humoral immune responses.

Poly(lactic acid)/β-cyclodextrin based nanoparticles bearing ruthenium(II)-arene naproxen complex: preparation and characterisation. Analytical validation for metal determination by microwave-induced plasma optical emission spectrometry

The objectives of this work are to develop nanocarrier systems for the Ru(II)-p-cymene naproxen antitumor metallodrug, [Ru(η6-p-cymene)(npx)Cl] or Rupcy, based on polymeric nanoparticles (NPs) composed by the biodegradable poly(lactic acid) (PLA) and the hydrophilic polymerised β-cyclodextrin (PolyCD); to validate an analytical method for determination of Ru incorporated into the metallodrug loaded-NPs. The PolyCD was prepared by single step condensation and polymerisation reaction and incorporated as a polymer blend during the fabrication of PLA/PolyCD blends NPs and also as a core/shell structure built by adsorption of the PolyCD onto the surface of PLA NPs to give PLA(core)/PolyCD(shell) NPs. Three different loaded-systems incorporating the metallodrug (Rupcy-PLA NPs (1), Rupcy-PLA/PolyCD blends (2), and Rupcy-PLA(core)/PolyCD(shell) NPs (3)) were prepared by nanoprecipitation. The characterisation was performed by Proton Nuclear Magnetic Resonance, Matrix Assisted Laser Desorption/Ionization Time-of-Flight, Fourier-Transform Infra-red and UV-VIS Electronic Absorption Spectroscopies, Thermogravimetric Analysis, Differential Scanning Calorimetry, Dynamic Light Scattering, and Electrophoretic Light Scattering. Ru was determined by Microwave Induced Plasma Optical Emission Spectrometry (MIP-OES) with validation of the method. The metallodrug entrapment efficiency was around 90% (w/w) and drug loading was at 3–4% (w/w). The characterised metallodrug-loaded systems exhibited monomodal size distributions and appropriate hydrodynamic diameters [218.3 ± 13.5 (1), 205.4 ± 14.4 (2), 231.5 ± 22.0 (3) nm] and zeta potential values [−31.5 ± 2.2 (1), −26.1 ± 4.5 (2), −28.8 ± 6.1 (3) mV]. The validation of the MIP-OES method by evaluating selectivity, linearity, precision, accuracy, and limits of detection and quantification succeeded. The NPs parameters are compatible with colloidally stable systems. The MIP-OES method showed to be simple, reliable, and feasible to quantify indirectly the amount of the metallodrug-loaded into the PLA NPs.

Preparation of PLA-TPU-Nanoclay composites and characterization of their morphological, mechanical, and shape memory properties

In this study, a combination of polylactic acid polymer and thermoplastic polyurethane with the addition of nano-clay particles was used. The reason for using clay nanoparticles and their strength is the low price and availability of this material. Adding nano-clay particles to the polymer composition improves the mechanical properties of the composite as they will interact with functional groups of the polymer.The results of the FTIR spectroscopy confirmed the presence of three components in the compound indicating that no chemical reactions occurred among the three components during the compounding process. The FE-SEM images taken from the compounds showed that TPU and nano-clay particles were evenly distributed in the PLA matrix. The DMTA results were utilized to determine the transfer temperature of the compounds as well as the storage and loss modulus and the shape memory properties. The XRD spectroscopy was used to determine the crystallinity and exfoliation of the nanoparticles. The mechanical properties of the fabricated polymer compounds were determined. It was found that the sample with 3% by weight of clay nanoparticles had the highest strength, and the sample with 5 wt% of clay nanoparticles had the highest toughness among nanocomposites. According to the hardness measurement, the sample with 5% by weight of clay nanoparticles has the highest hardness amongst all prepared composites. The memory properties of the prepared nanocomposites showed a significant improvement with increasing the amount of nanoparticles.This study showed the suitability and efficiency of PLA, TPU, and clay nanoparticle melt mixing methods in achieving a relatively tough shape memory composite. At the same time, this method is also inexpensive and scalable.

Protective Effects of Resveratrol Encapsulated In Liposomes or PLA Nanoparticles against Oxidative Stress in NRK-52E Cells

Liposomes and Polymeric nanoparticles are nanocarriers that can be used to enhance the pharmacokinetics of different drugs. The objective of the current study was to encapsulate resveratrol in DPPC liposomes and PLA nanoparticles; separately for the amelioration of PQ-induced oxidative stress on NRK-52E cells. Liposomes were produced by the hydration of a lipid film. Polymeric nanoparticles were prepared by double emulsification solvent diffusion method using PLA. They were then characterized for their particle size, zeta potential, drug loading, antioxidant activity, toxicity on NRK-52E cells, and protection against paraquat oxidation. The mean particle size for liposomes and PLA nanoparticles were respectively 197.4 ± 102.4 and 457.9 ± 56.1 nm and their surface zeta-potentials were -7.86 ± 6.36 and -21.6 ± 10.4 mV; respectively. LM and SEM images showed both types of nanoparticles to be spherical in shape. %LE efficiency for liposomes (12.04 ± 1.23%) was quite low compared to PLA nanoparticles (40.81 ± 29.14%). However, the % internalization for liposomes (5.95 ± 0.09%) was around 11 times higher than free resveratrol compared to PLA nanoparticles (0.93 ± 0.03%) which were only around two-fold higher. The toxicity tests showed that both liposomes and PLA nanoparticle forms of resveratrol showed less harmful effect on the cells than its free form mainly in the LDH assay. Furthermore, the benefit of encapsulation was also clear in the activity tests against PQ on the NRK-52E cell. From these results, it can be concluded that resveratrol-loaded liposomes and PLA nanoparticles can show more benefits over free resveratrol.

Biocompatible and Photostable Photoacoustic Contrast Agents as Nanoparticles Based on Bodipy Scaffold and Polylactide Polymers: Synthesis, Formulation, and In Vivo Evaluation.

We have designed a new Bodipy scaffold for efficient in vivo photoacoustic (PA) imaging of nanoparticles commonly used as drug nanovectors. The new dye has an optimized absorption band in the near-infrared window in biological tissue and a low fluorescence quantum yield that leads to a good photoacoustic generation efficiency. After Bodipy-initiated ring-opening polymerization of lactide, the polylactide-Bodipy was formulated into PEGylated nanoparticles (NPs) by mixing with PLA-PEG at different concentrations. Formulated NPs around 100 nm exhibit excellent PA properties: an absorption band at 760 nm and a molar absorption coefficient in between that of molecular PA absorbers and gold NPs. Highly improved photostability compared to cyanine-labeled PLA NPs as well as innocuity in cultured macrophages were demonstrated. After intravenous injection in healthy animals, NPs were easily detected using a commercial PA imaging system and spectral unmixing, opening the way to their use as theranostic agents.

Naturally Equipped Urinary Exosomes Coated Poly (2-ethyl-2-oxazoline)-Poly (D, L-lactide) Nanocarriers for the Pre-Clinical Translation of Breast Cancer.

Recently, biomimetic nanoparticles for tumor−targeted therapy have attracted intensifying interest. Although exosomes are an excellent biomimetic material, numerous challenges are still hindering its clinical applications, such as low yield, insufficient targeting efficiency, and high cost. In this work, urinary exosomes (UEs) with high expression of CD9 and CD47 were extracted from breast cancer patients by a non−invasive method. Here, a nanotechnology approach is reported for tumor homologous targeting via CD9 and phagocytosis escape via CD47 through UE−coated poly (2−ethyl−2−oxazoline)−poly (D, L−lactide) (PEOz−PLA) nanoparticles (UEPP NPs). The cytotoxic agent doxorubicin (DOX)−loaded UEPP (UEPP−D) NPs with an initial particle size of 61.5 nm showed a burst release under acidic condition mimicking the tumor microenvironment. In vitro experiments revealed that UEPP−D NPs exhibited significantly improved cellular uptake, cytotoxicity, and apoptosis in MCF−7 cell lines as compared to DOX−loaded PEOz−PLA nanoparticles (PP−D NPs) and free DOX. More importantly, anti−phagocytosis and pharmacokinetic studies confirmed that UEPP−D NPs had superior immune escape ability and significantly prolonged the drug’s bloodstream circulation in vivo. Finally, UEPP−D NPs showed a markedly higher antitumor efficacy and lower side−toxicity in MCF−7 tumor bearing nude mice model. Thus, this versatile nano−system with immune escape, homologous targeting, and rapid response release characteristics could be a promising tool for breast cancer treatment.

Multifunctional PLA/Gelatin Bionanocomposites for Tailored Drug Delivery Systems.

A series of bionanocomposites composed of shark gelatin hydrogels and PLA nanoparticles featuring different nanostructures were designed to generate multifunctional drug delivery systems with tailored release rates required for personalized treatment approaches. The global conception of the systems was considered from the desired customization of the drug release while featuring the viscoelastic properties needed for their ease of storage and posterior local administration as well as their biocompatibility and cell growth capability for the successful administration at the biomolecular level. The hydrogel matrix offers the support to develop a direct thermal method to convert the typical kinetic trapped nanostructures afforded by the formulation method whilst avoiding the detrimental nanoparticle agglomeration that diminishes their therapeutic effect. The nanoparticles generated were successfully formulated with two different antitumoral compounds (doxorubicin and dasatinib) possessing different structures to prove the loading versatility of the drug delivery system. The bionanocomposites were characterized by several techniques (SEM, DLS, RAMAN, DSC, SAXS/WAXS and rheology) as well as their reversible sol–gel transition upon thermal treatment that occurs during the drug delivery system preparation and the thermal annealing step. In addition, the local applicability of the drug delivery system was assessed by the so-called “syringe test” to validate both the storage capability and its flow properties at simulated physiological conditions. Finally, the drug release profiles of the doxorubicin from both the PLA nanoparticles or the bionanocomposites were analyzed and correlated to the nanostructure of the drug delivery system.

Uniformly Dispersed Poly(lactic acid)-Grafted Lignin Nanoparticles Enhance Antioxidant Activity and UV-Barrier Properties of Poly(lactic acid) Packaging Films.

Poly(lactic acid) (PLA) represents one of the most widely used biodegradable polymers for food packaging applications. While this material provides many advantages, it is characterized by limited antioxidant and UV-barrier properties. Blending PLA with lignin is an attractive strategy to address these limitations. Lignin possesses antioxidant properties and absorbs UV-light and is a widely available low value byproduct of the paper and pulp industry. This study has explored the use of lignin nanoparticles to augment the properties of PLA-based films. A central challenge in the preparation of PLA–lignin nanoparticle blend films is to avoid nanoparticle aggregation, which could compromise optical properties as well as antioxidant activity, among others. To avoid nanoparticle aggregation in the PLA matrix, PLA-grafted lignin nanoparticles were prepared via organocatalyzed lactide ring-opening polymerization. In contrast to lignin and unmodified lignin nanoparticles, these PLA-grafted lignin nanoparticles could be uniformly dispersed in PLA for lignin contents up to 10 wt %. The addition of as little as the equivalent of 1 wt % of lignin of these nanoparticles effectively blocked transmission of 280 nm UV-light. At the same time, these blend films retained reasonable visible light transmittance. The optical properties of the PLA lignin blend films also benefited from the well-dispersed nature of the PLA-grafted nanoparticles, as evidenced by significantly higher visible light transmittance of blends of PLA and PLA-grafted nanoparticles, as compared to blends prepared from PLA with lignin or unmodified lignin nanoparticles. Finally, blending PLA with PLA-grafted lignin nanoparticles greatly augments the antioxidant activity of these films.

Poly (Lactic Acid) Nanoparticles: A Promising Hope to Overcome the Cancers

Nanoparticles are used mainly for the transmission of the therapeutic molecules (like drugs, proteins, or DNA) to the organ/tissue of human body. Polymeric nanoparticles are mostly applied for therapeutic effectiveness in cancer therapy. The micro environment of tumor tissues in vessels can assist nanoparticles in achieving their anticipated accumulation. Poly (lactic acid)(PLA) is a novel green polymer with natural sources (like sweet potato and sugar cane). PLA is a linear aliphatic which has great sustainability, renewability and compostability. PLA has popper mechanical, thermal and barrier properties. This biomaterial is thermoplastic polyester with biocompatibility, non-toxicity and biodegradability. Various forms of PLA nanoparticles are synthetized for biomedical applications like cancer treatments and wound healing process. This review article introduces the various structures of polylactic acid nanoparticles used to deliver anticancer drugs. Furthermore, the investigational approaches that are considered for using PLA nanoparticles in treatment of different types of cancers will be reported briefly.

Nano-Architectonics of Antibiotic-Loaded Polymer Particles as Vehicles for Active Molecules

Recently, nanotechnology research studies have been proven that use of various nanoparticles as drug delivery systems to target and to annihilate pathogenic microorganisms may be a good solution for prevention and treatment of severe infection. In the last few years, antimicrobial drug encapsulation into nano-sized systems has materialized as a promising alternative that increased drug efficacy and minimized adverse effects. Physicochemical properties of erythromycin-loaded polymer nanoparticles were assessed using particle size distribution, HPLC, FTIR, TG/DTA, and SEM characterization techniques. The as-prepared samples exhibited an average particle size of 340 and 270 nm, respectively, with erythromycin content of 99.7% in both samples. From the release profile of erythromycin from PLA/PLGA, a prolonged drug release can be observed from both Ery-PLA and Ery-PLGA nanostructures. Morphology images exhibited spherical, rigid, and ring-shaped nanoparticles. Thermal analytical study in the case of Ery-PLA and Ery-PLGA samples showed that pure drug has an endothermic peak at around 150 °C assigned to a melting point. The antibiotic melting peak disappeared for both antibiotic-loaded PLA and PLGA nanoparticles thermographs, denoting the presence of erythromycin. This indicates that the antibiotic is uniformly dispensed throughout the host polymer matrix at nanometer scale. FTIR spectra of Ery-PLA and Ery-PLGA nano-architectures with almost similar peaks indicated no alteration in chemical structure of drug-loaded polymer nanoparticles.

A Polylactide-Based Micellar Adjuvant Improves the Intensity and Quality of Immune Response.

Micelles from amphiphilic polylactide-block-poly(N-acryloxysuccinimide-co-N-vinylpyrrolidone) (PLA-b-P(NAS-co-NVP)) block copolymers of 105 nm in size were characterized and evaluated in a vaccine context. The micelles were non-toxic in vitro (both in dendritic cells and HeLa cells). In vitro fluorescence experiments combined with in vivo fluorescence tomography imaging, through micelle loading with the DiR near infrared probe, suggested an efficient uptake of the micelles by the immune cells. The antigenic protein p24 of the HIV-1 was successfully coupled on the micelles using the reactive N-succinimidyl ester groups on the micelle corona, as shown by SDS-PAGE analyses. The antigenicity of the coupled antigen was preserved and even improved, as assessed by the immuno-enzymatic (ELISA) test. Then, the performances of the micelles in immunization were investigated and compared to different p24-coated PLA nanoparticles, as well as Alum and MF59 gold standards, following a standardized HIV-1 immunization protocol in mice. The humoral response intensity (IgG titers) was substantially similar between the PLA micelles and all other adjuvants over an extended time range (one year). More interestingly, this immune response induced by PLA micelles was qualitatively higher than the gold standards and PLA nanoparticles analogs, expressed through an increasing avidity index over time (>60% at day 365). Taken together, these results demonstrate the potential of such small-sized micellar systems for vaccine delivery.

Antioxidant and Cytotoxic Activities of Clove Oil Nanoparticles and Evaluation of Its Size and Retention Efficiency

A derivation of the nanoprecipitation technique without the presence of surfactants to reduce the nanoparticle size is herein proposed. The absence of surfactant in the nanoprecipitation technique allows capturing particles with a smaller diameter than nanoparticles containing surfactants, facilitating the migration of antioxidant nanoparticles in film packaging. Biodegradable PLA nanoparticles with clove oil were produced and characterized by dynamic light scattering, zeta potential, Fourier transform infrared spectroscopy, retention efficiency, cytotoxicity, and antioxidant activity. The particle sizes obtained were smaller than those commonly produced by nanoprecipitation, monodispersed and stable for 6 months. The antioxidant activity showed that the encapsulated form of clove oil had greater antioxidant activity than unencapsulated clove oil. The addition of PLA nanoparticles decreased the cytotoxic action of eugenol, the main antioxidant component of clove oil.

RBD Decorated PLA Nanoparticle Admixture with Aluminium Hydroxide Elicit Robust and Long Lasting Immune Response Against SARS-CoV-2

RBD Decorated PLA Nanoparticle Admixture with Aluminium Hydroxide Elicit Robust and Long Lasting Immune Response Against SARS-CoV-2

Novel Design Perspectives of PLA Nanoparticles for Drug Delivery

Novel Design Perspectives of PLA Nanoparticles for Drug Delivery

Zinc pthalocyanine loaded poly (lactic acid) nanoparticles by double emulsion methodology for photodynamic therapy against 9 L/LacZ gliosarcoma cells

Development delivery systems, such as nanoparticles, represent a growing area in biomedical research. Nanoparticles (NP) were prepared using a double-emulsion method to load zinc(II) phthalocyanine (ZnPc). NP were obtained using poly (lactic acid) (PLA). ZnPc is a second generation of photosensitizer used in photodynamic therapy (PDT). ZnPc loaded PLA nanoparticles (NPLA-ZnPc) were prepared by double-emulsion method, characterized and available in cellular culture. The mean nanoparticle size presented particle size was 384.7 ± 84.2 nm with polydispersity index (PDI) of 0.150 ± 0.015, and the encapsulation efficiency was of 83%. The nanoparticle formulations presented negative zeta potential values (−27.5 ± 1.0 mV), explaining their colloidal stability. ZnPc loaded nanoparticles maintain its photophysical behavior after encapsulation. Photosensitizer release from nanoparticles was sustained over 168 h with a biphasic ZnPc release profile. An in vitro phototoxic effect in range of 80% was observed in 9 L/LacZ gliosarcoma cells at laser light doses (10 J cm−2) with 3.0 µg mL−1 of NPLA-ZnPc. All the physical–chemical, photophysical and photobiological measurements performed allow us to conclude that ZnPc loaded PLGA nanoparticles is a promising drug delivery system for PDT.