Emulsion Solvent Evaporation 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.

Microencapsulation of Acalypha indica Linn. Extracts Using Chitosan-Polycaprolactone Blends

Polymer encapsulation is commonly adopted in drug delivery systems to form encapsulation that can assist in delivering active compounds to the targeted area. Acalypha indica (AI) crude extract was obtained from AI plants through ultrasound-assisted extraction. It is naturally unstable in the external environment and, thus, needs to be encapsulated to protect against volatility. Herein, this study emphasized the development of the encapsulations of AI extracts using a chitosan-polycaprolactone (PCL) blend by emulsion-solvent evaporation and freeze-dried methods. Four parameters for Al encapsulation were studied by fixing one parameter at a time. The percentage of encapsulation efficiency (EE%) was recorded as a response for each parameter. The study proceeded with central composite design (CCD) as the response surface methodology (RSM) optimization tool to study the interactions between the factors. Central points were taken from the preliminary data obtained in one-parameter experiments. The validation was carried out with two data of the highest and lowest EE% suggested by CCD. The highest EE% recorded was 98.70%, and the lowest EE% was 87.80%. The results showed a difference between predicted and experimental values at a percentage lower than 7.5%. Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscopy (SEM), particle size analyzer, and zeta potential were used to analyze the properties of selected microencapsulated samples. Overall, the encapsulation of AI extracts was successful and has the potential to be used in drug delivery.

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.

Ursolic acid loaded tri-block copolymer nanoparticles based on triphenylphosphine for mitochondria-targeted cancer therapy

A novel biodegradable amphiphilic triblock copolymer, polyphosphate, polyethylene glycol, and polylactic acid (PAEEP-PEG-PLLA), was synthesized by twice ring-opening polymerization and triphenylphosphine (TPP) was grafted onto the block copolymer to synthesize a carrier material TPP-PAEEP-PEG-PLLA, which was identified by 1H-nuclear magnetic resonance (1H-NMR) spectroscopy. The TPP-PAEEP-PEG-PLLA nanoparticles encapsulated with ursolic acid (UA) were prepared by the emulsion-solvent evaporation method and characterized by dynamic light scattering. The mitochondrial targeting ability of fluorescently labeled nanoparticles was evaluated by laser confocal microscopy. The average particle size and surface charge of the UA -loaded nanoparticle solution were 180.07 ± 1.67 nm and +15.57 ± 1.33 mV, respectively. The biocompatibility of nanoparticles was briefly evaluated by erythrocyte hemolysis assay. In vitro cell proliferation assay and scratch migration assay were performed to compare the difference in anti-tumor effect between UA and UA nanoparticles. The results showed that TPP-modified triblock copolymers had good mitochondrial targeting and improved the low bioavailability of UA, and UA nanoparticles exhibited more pronounced anti-tumor capabilities. In summary, the results suggested that our UA nanoparticles were a promising drug-targeted delivery system for the treatment of tumors.

Optimisation of microencapsulation efficiency of propolis phenolic compounds by double emulsion method using response surface methodology

AbstractThe aim of this study was to optimise the microencapsulation efficiency of propolis phenolic compounds by double emulsion solvent evaporation technique (W1/O/W2). The solvent/sample ratio and the polymer and surfactant concentration parameters were optimised using response surface methodology (RSM) through Box–Behnken Design (BBD). For each parameter studied, total phenolic content encapsulation efficiency (TPCEE), free radical scavenging activity (DPPH), and ferric reducing antioxidant power (FRAP) were evaluated. The results showed that the optimal parameters were: 31.60 mg mL−1 for sample/solvent ratio, 606.28 mg mL−1 for poly(ε-caprolactone) (PCL) concentrations, and 2.05 g mL−1 for poly(vinyl alcohol) (PVA) concentration. The optimum values obtained were: 84.62% for encapsulation efficiency of phenolic content, 51.89% for DPPH, and 48,733 mg Trolox Equivalent/100 g dry weight for FRAP. The experimental checking of results revealed the validity of elaborated models and their suitability for the prediction of both responses. The developed mathematical models have expressed a high level of significance through RSM optimisation processes for phenolic antioxidants of propolis.

Polymeric Propranolol Nanoparticles for Intraocular Delivery: Formulation, Characterization, and Vitreous Pharmacokinetics.

Recent studies have reported the promising effect of intravitreal propranolol on retinal neovascularization. However, rapid clearance and short half-life of the drug in the vitreous are the main drawbacks of this therapeutic approach. This study investigates the extension of the residence time of propranolol in the vitreous by polymeric nanoparticles (NPs) with the prospect of improving choroidal neovascularization treatment. The poly (lactic-co-glycolic) acid (PLGA) NPs were fabricated by a modified double emulsion solvent evaporation method and the obtained NPs were characterized for their size, poly dispersity index (PDI), and surface image. The in vitro release, cell cytotoxicity, and uptake of NPs were also evaluated. To investigate the effect of the vitreous pharmacokinetic drug loaded NPs versus that of the free propranolol, they were intravitreally injected into the rabbits' eyes and the drug vitreous concentrations in defined intervals were analyzed by high performance liquid chromatography (HPLC). The spherical NPs with about 230 nm size, and almost 10% drug loading were obtained. Based on the 3-(4, 5-Dimethylthiazol-2-Yl)-2, 5-Diphenyltetrazolium Bromide (MTT) outcomes, 30 µg/ml of propranolol was considered as the guide dosage in the intravitreal injection. Confocal microscopy images verified the presence of labeled NPs in the posterior segment after five days of receiving the injection. In vivo assay revealed that the vanishing rate of propranolol in rabbits treated with propranolol NPs was reduced at twice the rate as compared to that of the vanishing rate experienced with only the free drug. PLGA NPs can prolong the existence of propranolol in both vitreous and posterior ocular tissues, and thus, may provide an effective approach in treatment of posterior segment neovascularization.

Formulation and Evaluation of Floating Microspheres

Gastro-retentive dosage forms have potential for use as controlled- release drug delivery systems. Gastro retentive floating drug delivery systems have a bulk density lower than that of gastric fluids and thus increase residence time of drug in stomach and provide controlled delivery of many drugs. The aim of the present study is formulation and characterization of floating microspheres using model drug. Floating microspheres were prepared by oil-in-water emulsion solvent evaporation technique using ethyl cellulose as release retarding polymers. The floating microspheres were evaluated for percentage yield (%), particle size, drug content, drug entrapment efficiency, in-vitro floating ability and in-vitro drug release studies. The surface morphology of prepared microspheres was characterized by scanning electron microscopy. The microspheres were found to be spherical in shape and porous in nature. Compatibility studies were performed by fourier transform infrared (FTIR) technique. The prepared microspheres showed prolonged drug release of 12 h and remain buoyant for more than 12 h. In-vitro release kinetics were studied in different release kinetics models like zero order, first order model. It was concluded that developed floating microspheres offers a suitable and practical approach for prolonged release of drug over an extended period of time and thus oral bioavailability, efficacy and patient compliance is improved

Development of Hydroxyapatite/Polycaprolactone Composite Biomaterials for Laser Powder Bed Fusion: Evaluation of Powder Characteristics, Mechanical Properties and Biocompatibility.

Hydroxyapatite/polycaprolactone (HA/PCL) composites have been extensively explored in laser powder bed fusion (L-PBF) for bone tissue engineering. However, conventional mechanical mixing methods for preparing composite powders often yield inhomogeneous compositions and suboptimal flowability. In this study, HA/PCL powders were prepared and optimized for L-PBF using the modified emulsion solvent evaporation method. The morphology, flowability and thermal and rheological properties of the powders were systematically investigated, along with the mechanical and biological properties of the fabricated specimens. The HA/PCL powders exhibited spherical morphologies with a homogeneous distribution of HA within the particles. The addition of small amounts of HA (5 wt% and 10 wt%) enhanced the processability and increased the maximum values of the elastic modulus and yield strength of the specimens from 129.8 MPa to 166.2 MPa and 20.2 MPa to 25.1 MPa, respectively, while also improving their biocompatibility. However, excessive addition resulted in compromised sinterability, thereby affecting both mechanical and biological properties.

Inhibiting Effect of Cationic Procyanidin Nanoparticles on Drug-Resistant Oral Squamous Cell Carcinoma Cell Lines

Background: Multidrug resistance (MDR) is one of the primary causes of tumor chemotherapy failure. Therefore, it is essential to uncover new drug treatment protocols. In the current study, employing chitosan (CS) and sodium tripolyphosphate (TPP) as carriers and cross-linking agents, the proanthocyanidins (PHL)/poly (lactic-co-glycolic acid) (PLGA) were encapsulated by emulsion solvent evaporation, through which the cationic CS-PLGA-PHL nanosystem was obtained. The effectiveness of CS-PLGAPHL on the invasion and migration of human oral squamous cell carcinoma cells was discussed, as were their potential mechanisms. Materials and Methods: A CS-PLGA-PHL nanosystem was constructed by emulsion-solvent evaporation. The size distribution, dispersion, and morphology were characterised by the laser particle size analyser and transmission electron microscope. Human oral squamous cell carcinoma drug-resistant cell lines SCC131/R and SCC-15/DDP were cultured in vitro. The two cell types were induced at different concentrations by CS-PLGA-PHL, after which a CCK⁃8 experiment was performed to determine the effect of CS-PLGA-PHL on the proliferation of the two cell lines. The 50% inhibitory concentration (IC50) of CSPLGA- PHL was calculated at different time points. The transwell chamber experiment was performed to identify the effects of CS-PLGA-PHL on the migration and invasion of OSCC cells. The expression levels of MMP-2 and MMP-9 were detected by Western blot and q-PCR. Results: CS-PLGA-PHL is well dispersed. The PDI appeared to be lowest when the mass ratio of chitosan to PLGA equaled 1:15. CS-PLGA-PHL exhibited a marked effect in inhibiting the proliferation of SCC- 131/R and SCC-15/DDP as well as the invasion and migration. CS-PLGA-PHL was able to downregulate the expression of MMP-2 and MMP-9 genes and proteins significantly in drug-resistant cell lines. Conclusion: CS-PLGA-PHL for oral squamous cell carcinoma has been successfully prepared to exert significant inhibition on the proliferation, invasion, and migration of OSCC cells. The mechanism involved was possibly related to the down-regulation of MMP-2 and MMP-9 expression by CS-PLGA-PHL.

Pharmacokinetic and Pharmacodynamic Evaluation of Telmisartan-loaded Novel Curcumin-tagged Solid Nanodispersion for the Treatment of Diabetic Nephropathy in an Animal Model

Aim: This study aimed to evaluate the therapeutic efficacy of telmisartan-loaded novel curcumin-tagged solid nanodispersion in streptozotocin-nicotinamide-induced diabetic nephropathy in Wistar rats. Objective: The objective of this study was to perform a comprehensive pharmacokinetic and pharmacodynamic evaluation of a novel curcumin-tagged solid nanodispersion loaded with telmisartan, with the aim of assessing its potential as a treatment for diabetic nephropathy in an animal model. Specifically, the following objectives will be addressed: formulation and character-ization, in vitro evaluation, pharmacokinetics and pharmacodynamics evaluation, and compara-tive analysis. Materials and Methods: Telmisartan-loaded curcumin-tagged solid nanodispersion was prepared using the emulsion solvent evaporation method. The optimized formulation was evaluated for pharmacokinetic and pharmacodynamic parameters in an animal model. Wistar rats were divided into 5 groups, with 6 animals in each group. Diabetes was induced using nicotinamide (240 mg/kg) and streptozotocin (55 mg/kg, i.p.) injections in the animals. After 30 to 45 days of intro-duction, diabetic nephropathy was manifested. The kidneys and pancreas were used for histological analysis and renal and pancreatic damage assessment. Results: In-vivo studies showed better bioavailability with the t1/2 and Cmax of TLS-15 was 14.92 ± 0.47 hours and 0.32 ± 0.009, respectively, within 2 hours as compared to the t1/2 and Cmax of MP was 4.38 ± 0.19 hours and 0.19 ± 0.008 owing to the better dissolution due to solubility improvement. When compared to the commercially available product, TLS-15 was found to have blood glucose and body weight that were, respectively, 1.01 and 1.03 times higher. Kidney measures, such as serum urea and creatinine, were found to be 0.71 and 1.16 times lower for TLS-15, respectively, and albumin had a value that was 1.13 times higher than for the commercial formulation. Urine indicators, urine albumin, and creatinine estimations, as well as cytokine estimations, revealed that TLS-15 had creatinine levels that were 1.17 times higher and IL-6 lev-els that were 0.77 times higher than those of a commercial batch. Conclusion: The findings strongly support the renoprotective and pancreatic protective effects of TLS and Cur (SND-Solid Nanodispersion) combined by lowering levels of cytokines factor (IL-6), kidney, and lipid parameters. The postulated mechanism might be the combined inhibitory action of TLS and Cur.

Synthesis and evaluation of bone targeting PLGA nanoparticles loaded with components of traditional Chinese medicine formulas.

Targeted nanoparticles' preparation can enhance local drug concentration and reduce the side effects of drugs in non-targeted organs. At present, many patents have been applied for in the field of bone-targeted nanoparticles' preparations. They play an important role in the treatment and diagnosis of diseases. In this experiment, nanoparticles with bone targeting function were prepared by poly(lactic-co-glycolic acid) (PLGA) copolymer and tetracycline. These nanoparticles contain active ingredients in the Huangqi Sanxian decoction, a kind of Traditional Chinese Medicine (TCM) compound formula. These nanoparticles are predicted to be useful in the treatment of osteoporosis. Synthesis of tetracycline targeting groups was performed by acylation reaction, and PLGA nanoparticles were prepared by the Emulsification-solvent Evaporation Method. The appearance and particle size of the product were evaluated, and the effects of nanoparticles on the physiological activities of osteoblasts were observed. Finally, the bone-targeting ability of targeted nanoparticles in vivo and in vitro was investigated. The average particle size of the nanoparticles was about 200 nm, and the average drug entrapment was 60%. In vitro evaluation of osteoblasts assay showed that the nanoparticles can be well taken by cells. Their good biocompatibility and sustained-release properties reduce the toxic side effects of drugs when they promote osteoblasts' physiological activities. The results of the in vitro and in vivo bone targeting ability assays showed that tetracycline modified nanoparticles could effectively accumulate in the bone, indicating the great bone-targeting ability of the nanoparticles. The use of PLGA to load active components in the TCM compound formulas and remodel targeting groups is expected to improve drug efficacy, reduce drug dosage, and effects on non- action sites. This may provide new ideas for the development of TCM compound dosage forms. In summary, we prepared PLGA nanoparticles of multiple TCM ingredients with bone targeting ability, and they had good morphological appearance, and a promoting effect on various physiological activities of osteoblasts.

Quality-by-Design Based Development of Doxycycline Hyclate-Loaded Polymeric Microspheres for Prolonged Drug Release.

This study explores a novel approach to address the challenges of delivering highly water-soluble drug molecules by employing hydrophobic ion-pairing (HIP) complexes within poly (lactic-co-glycolic acid) (PLGA) microspheres. The HIP complex, formed between doxycycline hyclate (DH) and docusate sodium (DS), renders the drug hydrophobic. The development of the microspheres was done using the QbD approach, namely, Box-Behnken Design (BBD). A comprehensive characterization of the HIP complex confirmed the successful conversion of DH. DH and the HIP complex were effectively loaded into PLGA microspheres using the oil-in-water (O/W) emulsion solvent evaporation method. Results demonstrated significant improvements in percentage entrapment efficiency (% EE) and drug loading (% DL) for DH within the HIP complex-loaded PLGA microspheres compared to DH-loaded microspheres alone. Additionally, the initial burst release of DH reduced to 3% within the initial 15min, followed by sustained drug release over 8days. The modified HIP complex strategy offers a promising platform for improving the delivery of highly water-soluble small molecules. It provides high % EE, % DL, minimal initial burst release, and sustained release, thus having the potential to enhance patient compliance and drug delivery efficiency.

Polylactic Glycolic Acid-Mediated Delivery of Plectasin Derivative NZ2114 in Staphylococcus epidermidis Biofilms.

Antimicrobial peptides (AMPs) are antibiotic candidates; however, their instability and protease susceptibility limit clinical applications. In this study, the polylactic acid-glycolic acid (PLGA)-polyvinyl alcohol (PVA) drug delivery system was screened by orthogonal design using the double emulsion-solvent evaporation method. NZ2114 nanoparticles (NZ2114-NPs) displayed favorable physicochemical properties with a particle size of 178.11 ± 5.23 nm, polydispersity index (PDI) of 0.108 ± 0.10, ζ potential of 4.78 ± 0.67 mV, actual drug-loading rate of 4.07 ± 0.37%, encapsulation rate of 81.46 ± 7.42% and cumulative release rate of 67.75% (120 h) in PBS. The results showed that PLGA encapsulation increased HaCaT cell viability by 20%, peptide retention in 50% serum by 24.12%, and trypsin tolerance by 4.24-fold. Meanwhile, in vitro antimicrobial assays showed that NZ2114-NPs had high inhibitory activity against Staphylococcus epidermidis (S. epidermidis) (4-8 μg/mL). Colony counting and confocal laser scanning microscopy (CLSM) confirmed that NZ2114-NPs were effective in reducing the biofilm thickness and bacterial population of S. epidermidis G4 with a 99% bactericidal rate of persister bacteria, which was significantly better than that of free NZ2114. In conclusion, the results demonstrated that PLGA nanoparticles can be used as a reliable NZ2114 delivery system for the treatment of biofilm infections caused by S. epidermidis.

Self‐healing efficiency of cinnamaldehyde‐crosslinked soy protein resins with elongated soy protein microcapsules

AbstractSelf‐healing green thermoset soy protein isolate (SPI) based resins, crosslinked with cinnamaldehyde (CA), were developed. Self‐healing was achieved using elongated microcapsules (MCs) as against spherical MCs that have been used in most earlier studies. MCs containing SPI solution as healant within poly(d,l‐lactide‐co‐glycolide) shells were prepared using Water‐in‐oil‐in‐water (w/o/w) emulsion solvent evaporation (ESE) technique. Process parameters such as sodium tripolyphosphate (STP) and poly(vinyl alcohol) (PVA) concentrations and stirring speed were optimized to obtain elongated MCs. The average aspect ratio of MCs was over four. SPI resins crosslinked with 10% CA (10%CA‐SPI) increased Young's modulus and fracture stress by 54% and 87%, respectively, compared with their noncrosslinked counterpart. The resins containing 15% elongated MCs (15%MC‐10%CA‐SPI) showed self‐healing efficiencies of over 42% in fracture stress and about 35% in toughness recovery, after 24 h of healing. Improvement in self‐healing can be attributed to the high aspect ratio of the MCs that increases the probability of MCs being in the path of the microcracks and releasing the healant. Elongated MCs also contain higher amount of healant than spherical ones of same diameter. Self‐healing resins and composites can not only help prevent their premature failure but also improve their performance as well as service life and safety.

Synthesis and characterization of tenofovir disoproxil fumarate loaded nanoparticles for HIV‐1 treatment

AbstractThe remarkable ability of the human immunodeficiency virus (HIV) to evade the host's immune system and conventional antiretroviral therapy, has posed significant challenges in achieving complete eradication of the virus in people living with HIV (PLWHIV). However, nanotechnology has emerged as promising avenue for addressing some of the obstacles associated with the use of antiretroviral drugs by modifying drug molecules in nanoscale dimensions. Hence, the present study explores the utilization of poly(epsilon‐caprolactone) (PCL) as a carrier for encapsulating tenofovir disoproxil fumarate (TDF), offering an alternative treatment approach for HIV infection. TDF‐loaded polymeric nanoparticles were successfully prepared using double emulsion solvent evaporation technique and characterized. The characterization of TDF‐loaded polymeric nanoparticles at varied drug to polymer ratios showed that TDF was loaded in PCL with an encapsulation efficiency and drug loading capacity in the range of 23–46% and 4.8–19.9%, respectively. Of note, the neutralization efficacy of TDF‐loaded polymeric nanoparticles was more improved compared to free TDF. Encapsulation of TDF with PCL did not hinder the antiviral activity of TDF against HIV‐1 infection but rather enhanced its potency.

Development of novel polymer haemoglobin based particles as an antioxidant, antibacterial and an oxygen carrier agents

This innovative work aims to develop highly biocompatible and degradable nanoparticles by encapsulating haemoglobin (Hb) within poly-ε-caprolactone for novel biomedical applications. We used a modified double emulsion solvent evaporation method to fabricate the particles. A Scanning electron microscope (SEM) characterized them for surface morphology. Fourier Transform Infrared Spectroscopy (FTIR) and Ultraviolet–visible spectroscopies (UV–visible) elucidated preserved chemical and biological structure of encapsulated haemoglobin. The airproof equilibrium apparatus obtained the oxygen-carrying capacity and P50 values. The DPPH assay assessed free radical scavenging potential. The antibacterial properties were observed using four different bacterial strains by disk diffusion method. The MTT assay investigates the cytotoxic effects on mouse fibroblast cultured cell lines (L-929). The MTT assay showed that nanoparticles have no toxicity over large concentrations. The well-preserved structure of Hb within particles, no toxicity, high oxygen affinity, P50 value, and IC50 values open the area of new research, which may be used as artificial oxygen carriers, antioxidant, and antibacterial agents, potential therapeutic agents as well as drug carrier particles to treat the cancerous cells. The novelty of this work is the antioxidant and antibacterial properties of developed nanoparticles are not been reported yet. Results showed that the prepared particles have strong antioxidant and antibacterial potential.

Abstract WP315: Pharmacological Validation of Advanced Gamma Peptide Nucleic Acid (PNA) Based miR Inhibitors for Ischemic Stroke Treatment

Backgrounds: Our prior work demonstrated the potential of targeting miR-141-3p to mitigate ischemic stroke damage. In this study, we aimed to synthesize and validate more advanced and efficacious gamma peptide nucleic acid (PNA) based anti-miR 141-3p inhibitors, comparing them with regular PNA and phosphothiorate (PS) based counterparts. These inhibitors were subsequently encapsulated in poly(lactide-co-glycolide) (PLGA)-based nanoparticles (NPs) for treatment in a mouse model of ischemic stroke. Methods: In-house synthesis yielded PS, PNA, and gamma-PNA anti-miR 141-3p, encapsulated in PLGA NPs via double emulsion solvent evaporation. After physiochemical characterization, in vitro safety and efficacy were evaluated in HEK293 cells via MTT, LDH cytotoxicity assays, and qPCR for gene expression. In vivo efficacy studies employed the most potent gamma-PNA based anti-miR 141-3p, administered intraperitoneally 4 hours after 60-minute of transient middle cerebral artery occlusion (MCAO). Mice were sacrificed at 3 (acute) or 30 (chronic) days post-stroke. Acute cohort brain tissues were analysed for miRNA and target mRNA levels, along with infarct volume. Chronic cohort mice were subjected to weekly behavioral task to major sensorimotor deficit or recovery. Results: twenty-four-hour exposed HEK-293 cells were no sign of mortality and toxicity at concentration range of 0.015-1.5ug/mL of various anti-miR 141-3p. Gamma-PNA based anti-miR exhibited notably higher efficacy in inhibiting miR-141-3p (IC50=0.05ug/mL) compared to PS (IC50>1.5ug/mL) or regular PNA (IC50>1.5ug/mL). A single dose of gamma-PNA-based anti-miR significantly reduced (P<0.05 vs. Scramble control) infarct injury and brain tissue miR-141-3p levels (>2-fold vs. scramble control). Gamma-PNA treatment also led to swift improvement in sensorimotor deficits in the rotarod task. Conclusion: NPs of gamma-PNA-based anti-miR 141-3p were both safe and potent in vitro and in vivo. They effectively mitigated infarct injury, improved neurobehavioral deficits, demonstrating promising translational potential for ischemic stroke treatment. In future we aim to explore more mechanistic studies to explore it mode of action.

Development and In Vivo Evaluation of Sustained Release Microparticles Loaded with Levothyroxine for Hypothyroidism Treatment

Hypothyroidism is a chronic condition combated by a daily oral supplementation of levothyroxine. In addition to the need for frequent dosing, oral administration may result in variable absorption of the drug leading to a failure in achieving normal thyroid function. Therefore, the development of a long-acting injectable system capable of delivering the drug is necessary. This work was aimed at developing sustained release microparticles loaded with levothyroxine. The microparticles were produced through the emulsification-solvent evaporation method using 2 grades of biocompatible and biodegradable polyesters: poly(ᴅ,ʟ-lactide-co-glycolide) (PLGA) and poly(ᴅ,ʟ-lactide) (PLA). Both polymers produced microparticles with very similar sizes (1.9 µm) and zeta potential values (around -22.0 mV). However, PLA microparticles had a significantly higher drug loading (6.1% vs. 4.4%, respectively) and encapsulation efficiency (36.8%, vs. 26.1%, respectively) when compared to PLGA counterparts. While both types of microparticles displayed a biphasic release pattern in vitro, a slower rate of release was observed with PLA microparticles. Moreover, a similar biphasic release pattern was found in vivo, with an initial phase of rapid release followed by a slower phase in the subsequent 10 days. These results indicate the possibility of developing levothyroxine loaded polyester microparticles as a potential long-acting thyroid hormone replacement therapy.

Aerosolizable Pyrazinamide-Loaded Biodegradable Nanoparticles for the Management of Pulmonary Tuberculosis.

Background: Pyrazinamide is a Biopharmaceutical Classification System class III antibiotic indicated for active tuberculosis. Methods: In the present work, pyrazinamide-loaded biodegradable polymeric nanoparticles (PNPs) based dry powder inhaler were developed using the double emulsion solvent evaporation technique and optimized using design of experiments to provide direct pulmonary administration with minimal side effects. Batches were characterized for various physicochemical and aerosol performance properties. Results: Optimized batch exhibited particle size of 284.5 nm, % entrapment efficiency of 71.82%, polydispersibility index of 0.487, zeta potential of -17.23 mV, and in vitro drug release at 4 hours of 79.01%. Spray-dried PNPs were evaluated for drug content, in vitro drug release, and kinetics. The particle mass median aerodynamic diameter was within the alveolar region's range (2.910 μm). In the trachea and lung, there was a 2.5- and 1.2-fold increase in in vivo deposition with respect to pure drug deposition, respectively. In vitro drug uptake findings showed that alveolar macrophages with pyrazinamide PNPs had a considerably higher drug concentration. Furthermore, accelerated stability studies were carried out for the optimized batch. Results indicated no significant change in the evaluation parameters, which showed stability of the formulation for at least a 6-month period. Conclusion: PNPs prepared using biodegradable polymers exhibited efficient pulmonary drug delivery with decent stability.

Nanoparticle‐based sustained drug delivery for the treatment of ocular neovascular diseases

Aims/Purpose: Nanoparticles have shown great potential as a drug delivery system for the treatment of neovascular ocular diseases characterized by the growth of abnormal blood vessels in the retina. The current standard of therapy for neovascular ocular diseases involves administering monoclonal antibody‐based anti‐VEGF drugs via intravitreal injections on a periodic basis. The short half‐lives of these drugs necessitate frequent injections, which can limit the effectiveness of the treatments. Hence, there is a need to develop new approaches for enhanced bioavailability and sustained and long‐lasting delivery of anti‐VEGF drugs. The aim of this study was to utilize poly (glycerol sebacate) (PGS) nanoparticles to achieve an extended release of anti‐VEGF (anti‐vascular endothelial growth factor) drugs, with the objective of reducing the frequency of intravitreal injections required for treatment.Methods: Double emulsion solvent evaporation method was utilized for the synthesis of PGS nanoparticles. Nanoparticle size and polydispersity index (PDI) were determined with dynamic light scattering method.Results: Nanoparticles were synthesized with a size of approximately 150 nm and PDI less than 0.3. The encapsulation efficiency of nanoparticles loaded with anti‐VEGF drugs was found to be 74%. The 30% drug release from nanoparticles in the first 2 months indicates that nanoparticles are a promising candidate for sustained drug release applications. Cell‐viability studies showed that anti‐VEGF drug‐loaded nanoparticles did not exhibit toxicity to ARPE‐19 cells, but they did exhibit anti‐angiogenesis properties by inhibiting the growth of HUVEC cells in a concentration‐dependent manner.Conclusions: The development of new‐generation materials for the storage and preservation of anti‐VEGF drugs, as well as their enhancement with prolonged release, will considerably improve the efficacy of long‐term treatment strategies for ocular neovascular diseases.