Effect of process and formulation parameters on polycaprolactone nanoparticles prepared by solvent displacement

Multicomponent biopolymer hydrogels based on polycaprolactone with the combination of nano silver and linalool for the healing of infectious wounds

This study aimed to develop novel hydrogels using polycaprolactone (PCL), nano-silver (Ag), and linalool (Lin) to address the challenge of increasing antimicrobial resistance in healing infected wounds. The hydrogels' morphological properties, in vitro release profiles, antibacterial efficacy, and safety were investigated. Hydrogels were prepared from PCL/Ag, PCL/Lin, and PCL/Ag/Lin formulations and applied to infected wounds. Assessments included wound closure rates, bacterial counts, histopathological parameters, and immunofluorescence staining for Ki-67, keratinocyte growth factor (KGF), collagen type I (COL1A), vascular endothelial growth factor (VEGF), extracellular signal-regulated kinases 1 and 2 (ERK1/2), cluster of differentiation 206 (CD206), cluster of differentiation (CD31) and basic fibroblast growth factor (bFGF). The hydrogel structures demonstrated significant safety and antibacterial activity. Administration of hydrogels accelerated wound healing by reducing bacterial counts in granulation tissue and edema, while promoting fibroblast activity and epithelization. Additionally, there was increased expression of VEGF, CD31, ERK1/2, CD206, bFGF, Ki-67, KGF, and COL1A compared to control groups (P = 0.000). Synergistic interactions between Ag and Lin were observed in enhancing the wound healing process. In conclusion, these hydrogels effectively accelerated wound healing through antibacterial properties and modulation of gene expression.

Polyester nanoparticles delivering chemotherapeutics: Learning from the past and looking to the future to enhance their clinical impact in tumor therapy

Polymeric nanoparticles (NPs), specifically those comprised of biodegradable and biocompatible polyesters, have been heralded as a game-changing drug delivery platform. In fact, poly(α-hydroxy acids) such as polylactide (PLA), poly(lactide-co-glycolide) (PLGA), and poly(ε-caprolactone) (PCL) have been heavily researched in the past three decades as the material basis of polymeric NPs for drug delivery applications. As materials, these polymers have found success in resorbable sutures, biodegradable implants, and even monolithic, biodegradable platforms for sustained release of therapeutics (e.g., proteins and small molecules) and diagnostics. Few fields have gained more attention in drug delivery through polymeric NPs than cancer therapy. However, the clinical translational of polymeric nanomedicines for treating solid tumors has not been congruent with the fervor or funding in this particular field of research. Here, we attempt to provide a comprehensive snapshot of polyester NPs in the context of chemotherapeutic delivery. This includes a preliminary exploration of the polymeric nanomedicine in the cancer research space. We examine the various processes for producing polyester NPs, including methods for surface-functionalization, and related challenges. After a detailed overview of the multiple factors involved with the delivery of NPs to solid tumors, the crosstalk between particle design and interactions with biological systems is discussed. Finally, we report state-of-the-art approaches toward effective delivery of NPs to tumors, aiming at identifying new research areas and re-evaluating the reasons why some research avenues have underdelivered. We hope our effort will contribute to a better understanding of the gap to fill and delineate the future research work needed to bring polyester-based NPs closer to clinical application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Dynamic Release from Acetalated Dextran Nanoparticles for Precision Therapy of Inflammation

Polymer-based nanoparticles (NPs) that react to altered physiological characteristics have the potential to enhance the delivery of therapeutics to a specific area. These materials can utilize biochemical triggers, such as low pH, which is prone to happen locally in an inflammatory microenvironment due to increased cellular activity. This reduced pH is neutralized when inflammation subsides. For precise delivery of therapeutics to match this dynamic reaction, drug delivery systems (DDS) need to not only release the drug (ON) but also stop the release (OFF) autonomously. In this study, we use a systematic approach to optimize the composition of acetalated dextran (AcDex) NPs to start (ON) and stop (OFF) releasing model cargo, depending on local pH changes. By mixing ratios of AcDex polymers (mixed NPs), we achieved a highly sensitive material that was able to rapidly release cargo when going from pH 7.4 to pH 6.0. At the same time, the mix also offered a stable composition that enabled a rapid ON/OFF/ON/OFF switching within this narrow pH range in only 90 min. These mixed NPs were also sensitive to biological pH changes, with increased release in the presence of inflammatory cells compared to healthy cells. Such precise and controllable characteristics of a DDS position mixed NPs as a potential treatment platform to inhibit disease flare-ups, reducing both systemic and local side effects to offer a superior treatment option for inflammation compared to conventional systems.

Heating Capacity and Biocompatibility of Hybrid Nanoparticles for Magnetic Hyperthermia Treatment

Cancer is one of the deadliest diseases worldwide and has been responsible for millions of deaths. However, developing a satisfactory smart multifunctional material combining different strategies to kill cancer cells poses a challenge. This work aims at filling this gap by developing a composite material for cancer treatment through hyperthermia and drug release. With this purpose, magnetic nanoparticles were coated with a polymer matrix consisting of poly (L-co-D,L lactic acid-co-trimethylene carbonate) and a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer. High-resolution transmission electron microscopy and selected area electron diffraction confirmed magnetite to be the only iron oxide in the sample. Cytotoxicity and heat release assays on the hybrid nanoparticles were performed here for the first time. The heat induction results indicate that these new magnetic hybrid nanoparticles are capable of increasing the temperature by more than 5 °C, the minimal temperature rise required for being effectively used in hyperthermia treatments. The biocompatibility assays conducted under different concentrations, in the presence and in the absence of an external alternating current magnetic field, did not reveal any cytotoxicity. Therefore, the overall results indicate that the investigated hybrid nanoparticles have a great potential to be used as carrier systems for cancer treatment by hyperthermia.

Further Improvement Based on Traditional Nanocapsule Preparation Methods: A Review

Nanocapsule preparation technology, as an emerging technology with great development prospects, has uniqueness and superiority in various industries. In this paper, the preparation technology of nanocapsules was systematically divided into three categories: physical methods, chemical methods, and physicochemical methods. The technological innovation of different methods in recent years was reviewed, and the mechanisms of nanocapsules prepared via emulsion polymerization, interface polymerization, layer-by-layer self-assembly technology, nanoprecipitation, supercritical fluid, and nano spray drying was summarized in detail. Different from previous reviews, the renewal iteration of core-shell structural materials was highlighted, and relevant illustrations of their representative and latest research results were reviewed. With the continuous progress of nanocapsule technology, especially the continuous development of new wall materials and catalysts, new preparation technology, and new production equipment, nanocapsule technology will be used more widely in medicine, food, cosmetics, pesticides, petroleum products, and many other fields.

Curcumin and resveratrol delivery from multi-functionalized calcium phosphate scaffold enhances biological properties

Natural medicinal compounds (NMCs) can assist effectively in treating bone disorders. NMC release kinetics from a ceramic bone tissue engineering scaffold can be tailored. However, inferior physicochemical properties halt their therapeutic applications and need a carrier system for delivery. We developed a multi-functionalized scaffold to understand the effect of curcumin (Cur) and resveratrol (Rsv) on in vitro biological properties. Polycaprolactone (PCL) nanoparticles encapsulated resveratrol in the polymeric matrix. Nanoparticles showed a hydrodynamic diameter of about 180 nm, - 16 mV zeta potential, and up to ~65 % encapsulation efficiency. Scaffolds made of zinc-doped tricalcium phosphate (Zn-TCP) were coated with curcumin followed by either resveratrol (Cur-Rsv) or resveratrol nanoparticles (Cur-Rsv-NP). NMC-loaded scaffolds exhibited a biphasic release pattern over 60 days. Solubility and hydrophobic-hydrophilic interactions affected the NMC release profile. Resveratrol showed rapid release as compared to curcumin. The treated scaffold increased the cell viability of human fetal osteoblast (hFOB) by 1.8-fold as compared to the control. It exhibited a 6-fold increase in cytotoxicity toward osteosarcoma (MG-63) cells as compared to the untreated scaffold. NMCs loaded scaffold effectively inhibited Staphylococcus aureus from colonizing over the scaffold. Zinc doping enhanced osteoblast growth and prevented bacterial colony formation. Such design principle provided a direction for developing multi-functionalized calcium phosphate (CaP) scaffolds against bone diseases for orthopedic applications.

Chitosan functionalized PCL Nanoparticles Bearing Tyrosine Kinase Inhibitor Osimertinib Mesylate for Effective Lung Cancer Therapy

Lung cancer ranks second position among the cancer-related deaths. Osimertinib mesylate (OSM) is a tyrosine-kinase-inhibitor which can effectively treat NSCLC, but still there are certain limitations and side effects which could be circumvented by polymeric nanoparticles approach. Hence, this research was aimed to develop drug-loaded biodegradable poly caprolactone nanoparticles (PCL-NPs) such as OSM-loaded PCL-NPs (PCL-OSM-NPs) and chitosan fabricated OSM-loaded PCL-NPs (CS-PCL-OSM-NPs) to achieve active-targeting of OSM in the cancerous lung tissue. Thus CS-PCL-OSM-NPs enhances the anticancer efficacy due to active targeting nature and thereby reduces off-target side effects of OSM in the NSCLC treatment.Blank PCL-NPs, PCL-OSM-NPs, and CS-PCL-OSM-NPs were prepared by nanoprecipitation method. Optimized blank PCL-NPs, PCL-OSM-NPs, and CS-PCL-OSM-NPs exhibited the mean particle size of 90.2 ± 4.7nm, 167.7 ± 2.9nm, and 233.7 ± 4.8nm respectively. The %EE of PCL-OSM-NPs was found to be 68.4 ± 3.2%. In-vitro drug release study demonstrated sustained release profile of 69.5 ± 5% and 65.7 ± 1.5% for OSM from both the PCL-OSM-NPs and CS-PCL-OSM-NPs respectively. The PCL-OSM-NPs and CS-PCL-OSM-NPs demonstrated the inhibition of 82.2 ± 0.5% and 81.9 ± 0.2% in A549 cancer cells respectively which clearly signified the improved efficacy. Moreover, the PCL-OSM-NPs and CS-PCL-OSM-NPs exhibited significantly less haemolysis than OSM indicating safety of the formulation.These findings indicate that biohaemocompatibe CS-PCL-OSM-NPs is an attractive option to treat NSCLC with enhanced anticancer activity and reduced side effects.

Poly(succinimide) nanoparticles as reservoirs for spontaneous and sustained synthesis of poly(aspartic acid) under physiological conditions: potential for vascular calcification therapy and oral drug delivery

This paper describes the preparation of poly(succinimide) nanoparticles (PSI NPs) and investigates their properties and characteristics. Employing direct and inverse precipitation methods, stable PSI NPs with tunable size and narrow dispersity were prepared without the use of any stabilizer or emulsifier. It was demonstrated that PSI NPs convert to poly(aspartic acid) (PASP) gradually under physiological conditions (37 °C, pH 7.4), while remaining stable under mildly acidic conditions. The dissolution profile was tuned and delayed by chemical modification of PSI. Through grafting a fluorophore to the PSI backbone, it was also demonstrated that such a spontaneous conversion could offer great potential for oral delivery of therapeutic agents to the colon. Sustained PASP synthesis also contributed to a sustained reduction of reactive oxygen species induced by iron. Furthermore, PSI NPs effectively prevented in vitro calcification of smooth muscle cells. This was attributed to the chelation of calcium ions to PASP, thereby inhibiting calcium deposition, because under cell culture conditions PSI NPs serve as reservoirs for the sustained synthesis of PASP. Overall, this study sheds light on the preparation and features of biocompatible and biodegradable PSI-based NPs and paves the way for further research to discover as-yet unfulfilled potential of this polymer in the form of nanoparticles.

Enhancing the Antifungal Activity and Ophthalmic Transport of Fluconazole from PEGylated Polycaprolactone Loaded Nanoparticles

Fungal eye infections are caused mainly by an eye injury and can result in serious eye damage. Fluconazole (FLZ), a broad-spectrum antifungal agent, is a poorly soluble drug with a risk of hepatotoxicity. This work aimed to investigate the antifungal activity, ocular irritation, and transport of FLZ-loaded poly (ε-caprolactone) nanoparticles using a rabbit eye model. Three formulation factors affecting the nanoparticle's size, zeta potential, and entrapment efficiency were optimized utilizing the Box-Behnken design. Morphological characteristics and antifungal activity of the optimized nanoparticles were studied. The optimized nanoparticles were loaded into thermosensitive in situ hydrogel and hydroxypropylmethylcellulose (HPMC) hydrogel ophthalmic formulations. The rheological behavior, in vitro release and in vivo corneal transport were investigated. Results revealed that the percentage of poly (ε-caprolactone) in the nanoparticle matrix, polymer addition rate, and mixing speed significantly affected the particle size, zeta potential, and entrapment efficiency. The optimized nanoparticles were spherical in shape and show an average size of 145 nm, a zeta potential of -28.23 mV, and a FLZ entrapment efficiency of 98.2%. The antifungal activity of FLZ-loaded nanoparticles was significantly higher than the pure drug. The developed ophthalmic formulations exhibited a pseudoplastic flow, prolonged the drug release and were found to be non-irritating to the cornea. The prepared FLZ pegylated nanoparticles were able to reach the posterior eye segment without eye irritation. As a result, the developed thermosensitive in situ hydrogel formulation loaded with FLZ polymeric nanoparticles is a promising drug delivery strategy for treating deep fungal eye infections.

Spheroplexes: Hybrid PLGA-cationic lipid nanoparticles, for in vitro and oral delivery of siRNA

Vectorized small interfering RNAs (siRNAs) are widely used to induce gene silencing. Among the delivery systems used, lipid-based particles are the most effective. Our objective was the development of novel lipid-polymer hybrid nanoparticles, from lipoplexes (complexes of cationic lipid and siRNAs), and poly (lactic-co-glycolic acid) (PLGA), using a simple modified nanoprecipitation method. Due to their morphology, we called these hybrid nanoparticles Spheroplexes. We elucidated their structure using several physico-chemical techniques and showed that they are composed of a hydrophobic PLGA matrix, surrounded by a lipid envelope adopting a lamellar structure, in which the siRNA is complexed, and they retain surface characteristics identical to the starting nanoparticles, i.e. lipoplexes siRNA. We analyzed the composition of the particle population and determined the final percentage of spheroplexes within this population, 80 to 85% depending on the preparation conditions, using fluorescent markers and the ability of flow cytometry to detect nanometric particles (approximately 200 nm). Finally, we showed that spheroplexes are very stable particles and more efficient than siRNA lipoplexes for the delivery of siRNA to cultured cells. We administered spheroplexes contain siRNAs targeting TNF-α to mice with ulcerative colitis induced by dextran sulfate and our results indicate a disease regression effect with a response probably mediated by their uptake by macrophages / monocytes at the level of lamina propria of the colon. The efficacy of decreased level of TNF-α in vivo seemed to be an association of spheroplexes polymer-lipid composition and the specific siRNA. These results demonstrate that spheroplexes are a promising hybrid nanoparticle for the oral delivery of siRNA to the colon.

Modularity of RBC hitchhiking with polymeric nanoparticles: testing the limits of non-covalent adsorption

Red blood cell (RBC) hitchhiking has great potential in enhancing drug therapy, by improving targeting and reducing rapid clearance of nanoparticles (NPs). However, to improve the potential for clinical translation of RBC hitchhiking, a more thorough understanding of the RBC-NP interface is needed. Here, we evaluate the effects of NP surface parameters on the success and biocompatibility of NP adsorption to extracted RBCs from various species. Major differences in RBC characteristics between rabbit, mouse and human were proven to significantly impact NP adsorption outcomes. Additionally, the effects of NP design parameters, including NP hydrophobicity, zeta potential, surfactant concentration and drug encapsulation, on RBC hitchhiking are investigated. Our studies demonstrate the importance of electrostatic interactions in balancing NP adsorption success and biocompatibility. We further investigated the effect of varying the anti-coagulant used for blood storage. The results presented here offer new insights into the parameters that impact NP adsorption on RBCs that will assist researchers in experimental design choices for using RBC hitchhiking as drug delivery strategy.

Biodegradable Nanoparticles Loaded with Levodopa and Curcumin for Treatment of Parkinson's Disease

Background: Parkinson’s disease (PD) is the second most common age-related neurodegenerative disorder. Levodopa (L-DOPA) remains the gold-standard drug available for treating PD. Curcumin has many pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anti-amyloid, and antitumor properties. Copolymers composed of Poly (ethylene oxide) (PEO) and biodegradable polyesters such as Poly (ε-caprolactone) (PCL) can self-assemble into nanoparticles (NPs). This study describes the development of NH₂–PEO–PCL diblock copolymer positively charged and modified by adding glutathione (GSH) on the outer surface, resulting in a synergistic delivery of L-DOPA curcumin that would be able to pass the blood–brain barrier. Methods: The NH₂–PEO–PCL NPs suspensions were prepared by using a nanoprecipitation and solvent displacement method and coated with GSH. NPs were submitted to characterization assays. In order to ensure the bioavailability, Vero and PC12 cells were treated with various concentrations of the loaded and unloaded NPs to observe cytotoxicity. Results: NPs have successfully loaded L-DOPA and curcumin and were stable after freeze-drying, indicating advancing into in vitro toxicity testing. Vero and PC12 cells that were treated up to 72 h with various concentrations of L-DOPA and curcumin-loaded NP maintained high viability percentage, indicating that the NPs are biocompatible. Conclusions: NPs consisting of NH₂–PEO–PCL were characterized as potential formulations for brain delivery of L-DOPA and curcumin. The results also indicate that the developed biodegradable nanomicelles that were blood compatible presented low cytotoxicity.

Continuous Nanoprecipitation of Polycaprolactone in Additively Manufactured Micromixers

The polymeric ouzo effect is an energy-efficient and robust method to create nanoparticles with biologically degradable polymers. Usually, a discontinuous or semi-continuous process is employed due to its low technical effort and the fact that the amount of dispersions needed in a laboratory is relatively small. However, the number of particles produced in this method is not enough to make this process economically feasible. Therefore, it is necessary to improve the productivity of the process and create a controllable and robust continuous process with the potential to control parameters, such as the particle size or surface properties. In this study, nanoparticles were formulated from polycaprolactone (PCL) in a continuous process using additively manufactured micromixers. The main goal was to be able to exert control on the particle parameters in terms of size and zeta potential. The results showed that particle size could be adjusted in the range of 130 to 465 nm by using different flow rates of the organic and aqueous phase and varying concentrations of PCL dissolved in the organic phase. Particle surface charge was successfully shifted from a slightly negative potential of −14.1 mV to a negative, positive, or neutral value applying the appropriate surfactant. In summary, a continuous process of nanoprecipitation not only improves the cost of the method, but furthermore increases the control over the particle’s parameters.

Selective targeting of the novel CK-10 nanoparticles to the MDA-MB-231 breast cancer cells

The main objective of this project was to formulate novel decorated amphiphilic PLGA nanoparticles aiming for the selective delivery of the novel peptide (CK-10) to the cancerous/tumor tissue. Novel modified microfluidic techniques were used to formulate the nanoparticles. This technique was modified by using of Nano Assemblr associated with salting out of the organic solvent using K₂HPO₄. This modification is associated with higher peptide loading efficiencies, smaller size and higher uniformity. Size, zeta potential & qualitative determination of the adsorbed targeting ligands were measured by dynamic light scattering and laser anemometry techniques using the zeta sizer. Quantitative estimation of the adsorbed targeting ligands was done by colorimetry and spectrophotometric techniques. Qualitative and quantitative uptakes of the various PLGA nanoparticles were examined by the fluorescence microscope and the flow cytometer while the cytotoxic effect of the nanoparticles was measured by the colorimetric MTT assay. PLGA/poloxamer.FA, PLGA/poloxamer.HA, and PLGA/poloxamer.Tf have breast cancer MDA. MB321 cellular uptakes 83.8, 75.43 & 69.37 % which are higher than those of the PLGA/B cyclodextrin.FA, PLGA/B cyclodextrin.HA and PLGA/B cyclodextrin.Tf 80.87, 74.47 & 64.67 %. Therefore, PLGA/poloxamer.FA and PLGA/poloxamer.HA show higher cytotoxicity than PLGA/ poloxamer.Tf with lower breast cancer MDA-MB-231 cell viabilities 30.74, 39.15 & 49.23 %, respectively. The design of novel decorated amphiphilic CK-10 loaded PLGA nanoparticles designed by the novel modified microfluidic technique succeeds in forming innovative anticancer formulations candidates for therapeutic use in aggressive breast cancers.

Dose dependent safety implications and acute intravenous toxicity of aminocellulose-grafted-polycaprolactone coated gelatin nanoparticles in mice

Polymeric nanoparticles (NPs) are the most widely researched nanoformulations and gained broad acceptance in nanotherapeutics for targeted drug delivery and theranostics. However, lack of regulations, guidelines, harmonized standards, and limitations with their employability in clinical circumstances necessitates an in-depth understanding of their toxicology. Here, we examined the in-vivo toxicity of core-shell polymeric NPs made up of gelatin core coated with an outer layer of aminocellulose-grafted polycaprolactone (PCL-AC) synthesized for drug delivery purposes in inflammatory disorders. Nanoparticles were administered intravenously in Swiss albino mice, in multiple dosing (10, 25, and 50 mg/kg body weight) and outcomes of serum biochemistry analysis and histopathology evaluation exhibited that the highest 50 mg/kg administration of NPs altered biochemistry and histopathology aspects of vital organs, while doses of 10 and 25 mg/kg were safe and biocompatible. Further, mast cell (toluidine blue) staining confirmed that administration of the highest dose enhanced mast cell infiltration in tissues of vital organs, while lower doses did not exhibit any of these alterations. Therefore, the results of the present study establish that the NPs disposal in-vivo culminates into alterations in organ structure and function consequences such that lower doses are quite biocompatible and do not demonstrate any structural or functional toxicity while some toxicological effects start appearing at the highest dose.

Aminocellulose - grafted polycaprolactone-coated core-shell nanoparticles alleviate the severity of ulcerative colitis: a novel adjuvant therapeutic approach

Ulcerative colitis (UC) is an idiopathic inflammatory condition of colorectal regions. Existing therapies for UC face grave lacunae including off-target and other harmful side effects, extensive first-pass metabolism, rapid clearance, limited or poor drug absorption and various other limitations, resulting in lower bioavailability. These conditions demand advanced delivery strategies to inflammatory colonic conditions so that drugs can counter stomach acid, avail protective strategies at this pH and selectively deliver drugs to the colon. Therefore, this approach was undertaken to develop and characterize nanoparticles for the delivery of drugs glycyrrhizic acid as well as budesonide in UC. Biocompatible and biodegradable aminocellulose-conjugated polycaprolactone containing budesonide was covered onto gelatinous nanoparticles (NPs) loaded with GA. Nanoparticles were prepared by the solvent evaporation technique, which showed particle size of ∼230 nm, spherical shape, almost smooth morphological characters under transmission, scanning and atomic force microscopy. These NPs also improved disease activities like occult blood in the stool, length of the colon and fecal properties. The nanoparticle therapy appreciably decreased colonic mast cellular infiltration, significantly maintained mucin protection, ameliorated histological features of the colon. Furthermore, markers of inflammation such as iNOS, COX-2, IL1-β, TNF-α, NO, and MPO were also appreciably ameliorated with the therapy of dual drug-loaded nanoparticles. Overall, these results establish that dual drug-loaded core-shell NPs exhibit superior therapeutic properties over the free or naïve forms of GA and budesonide in acute colon inflammation and present advantages that may be assigned to their ability to significantly inhibit colon inflammatory conditions.

Exemestane encapsulated polymer-lipid hybrid nanoparticles for improved efficacy against breast cancer: optimization,in vitrocharacterization and cell culture studies

Polymer-lipid hybrid nanoparticles (PLHNPs) are novel nanoplatforms for the effective delivery of a lipophilic drug in the management of a variety of solid tumors. The present work was designed to develop exemestane (EXE) encapsulated D-alpha-tocopheryl polyethylene glycol succinate (TPGS) based PLHNPs (EXE-TPGS-PLHNPs) for controlled delivery of EXE for breast cancer management. EXE-TPGS-PLHNPs were formulated by single-step nano-precipitation technique and statistically optimized by a 3³Box-Behnken design using Design expert^®software. The polycaprolactone (PCL;X₁), phospholipon 90 G (PL-90G;X₂), and surfactant (X₃) were selected as independent factors while particles size (PS;Y₁), polydispersity index (PDI;Y₂), and %entrapment efficiency (%EE;Y₃) were chosen as dependent factors. The average PS, PDI, and %EE of the optimized EXE-TPGS-PLHNPs was observed to be 136.37 ± 3.27 nm, 0.110 ± 0.013, and 88.56 ± 2.15% respectively. The physical state of entrapped EXE was further validated by Fourier-transform infrared spectroscopy, differential scanning calorimetry, and powder x-ray diffraction that revealed complete encapsulation of EXE in the hybrid matrix of PLHNPs with no sign of significant interaction between drug and excipients.In vitrorelease study in simulated gastrointestinal fluids revealed initial fast release for 2 h after that controlled release profile up to 24 h of study. Moreover, optimized EXE-TPGS-PLHNPs exhibited excellent stability in gastrointestinal fluids as well as colloidal stability in different storage concentrations. Furthermore, EXE-TPGS-PLHNPs exhibited distinctively higher cellular uptake and time and dose-dependent cytotoxicity against MCF-7 breast tumor cells compared to EXE-PLHNPs without TPGS and free EXE. The obtained results suggested that EXE-TPGS-PLHNPs can be a promising platform for the controlled delivery of EXE for the effective treatment of breast cancer.

Cefotaxime Loaded Polycaprolactone Based Polymeric Nanoparticles with Antifouling Properties for In-Vitro Drug Release Applications

The objective of the present study was to achieve the successful encapsulation of a therapeutic agent to achieve antifouling functionality regarding biomedical applications. Considering nanotechnology, drug-loaded polycaprolactone (PCL)-based nanoparticles were prepared using a nano-precipitation technique by optimizing various process parameters. The resultant nano-formulations were investigated for in vitro drug release and antifouling applications. The prepared particles were characterized in terms of surface morphology and surface properties. Optimized blank and drug-loaded nanoparticles had an average size of 200 nm and 216 nm, respectively, with associated charges of -16.8 mV and -11.2 mV. Studies of the in vitro release of drug were carried out, which showed sustained release at two different pH, 5.5 and 7.4 Antifouling activity was observed against two bacterial strains, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The zone of inhibition of the optimized polymeric drug-loaded nanoparticle F-25 against both strains were compared with the pure drug. The gradual pH-responsive release of antibiotics from the biodegradable polymeric nanoparticles could significantly increase the efficiency and pharmacokinetics of the drug as compared to the pure drug. The acquired data significantly noted that the resultant nano-encapsulation of antifouling functionality could be a promising candidate for topical drug delivery systems and skin applications.

Aminocellulose-Grafted Polymeric Nanoparticles for Selective Targeting of CHEK2-Deficient Colorectal Cancer

We report the formulation of aminocellulose-grafted polymeric nanoparticles containing LCS-1 for synthetic lethal targeting of checkpoint kinase 2 (CHEK2)-deficient HCT116 colon cancer (CRC) cells to surpass the limitations associated with the solubility of LCS-1 (a superoxide dismutase inhibitor). Aminocellulose (AC), a highly biocompatible and biodegradable hydrophilic polymer, was grafted over polycaprolactone (PCL), and a nanoprecipitation method was employed for formulating nanoparticles containing LCS-1. In this study, we exploited the synthetic lethal interaction between SOD1 and CHEK2 for the specific inhibition of CHEK2-deficient HCT116 CRC cells using LCS-1-loaded PCL-AC NPs. Furthermore, the effects of formation of protein corona on PCL-AC nanoparticles were also assessed in terms of size, cellular uptake, and cell viability. LCS-1-loaded NPs were evaluated for their size, zeta potential, and polydispersity index using a zetasizer, and their morphological characteristics were assessed by transmission electron microscopy, scanning electron microscopy, and atomic force microscopy analyses. Cellular internalization using confocal microscopy exhibited that nanoparticles were uptaken by HCT116 cells. Also, nanoparticles were cytocompatible as they did not induce cytotoxicity in hTERT and HEK-293 cells. The LCS-1-loaded PCL-AC NPs were quite hemocompatible and were 240 times more selective in killing CHEK2-deficient cells as compared to CHEK2-proficient CRC cells. Moreover, PCL-AC NPs exhibited that the protein corona-coated nanoparticles were incubated in the human and fetal bovine sera as visualized by SDS-PAGE. A slight increment in hydrodynamic diameter was observed for corona-coated PCL-AC nanoparticles, and size increment was further confirmed by TEM. Corona-coated PCL-AC NPs also exhibited cellular uptake as demonstrated by flow cytometric analysis and did not cause cytotoxic effects on hTERT cells. The nanoformulation was developed to enhance therapeutic potential of the drug LCS-1 for enhanced lethality of colorectal cancer cells with CHEK2 deficiency.

Non-Ionic Surfactants for Stabilization of Polymeric Nanoparticles for Biomedical Uses

Surfactants are essential in the manufacture of polymeric nanoparticles by emulsion formation methods and to preserve the stability of carriers in liquid media. The deposition of non-ionic surfactants at the interface allows a considerable reduction of the globule of the emulsion with high biocompatibility and the possibility of oscillating the final sizes in a wide nanometric range. Therefore, this review presents an analysis of the three principal non-ionic surfactants utilized in the manufacture of polymeric nanoparticles; polysorbates, poly(vinyl alcohol), and poloxamers. We included a section on general properties and uses and a comprehensive compilation of formulations with each principal non-ionic surfactant. Then, we highlight a section on the interaction of non-ionic surfactants with biological barriers to emphasize that the function of surfactants is not limited to stabilizing the dispersion of nanoparticles and has a broad impact on pharmacokinetics. Finally, the last section corresponds to a recommendation in the experimental approach for choosing a surfactant applying the systematic methodology of Quality by Design.

Formation of pure nanoparticles with solvent-fractionated lignin polymers and evaluation of their biocompatibility

This study aimed to determine the effects of lignin characteristics (mainly molecular weight, functional groups, and internal linkages) on nanoparticle formation. First, five different lignin fractions (M_w 1460-12,900) were obtained from commercial kraft lignin (KL) by sequential solvent extraction. Functional groups and internal linkages were determined in lignin fractions, each fraction consisting of different levels and ratios. Second, spherical lignin nanoparticles (i.d. 193-1039 nm) were synthesized by nanoprecipitation at different pre-dialysis concentrations (1, 2, 4, and 6 mg mL^-1 THF) with the different fractions (F1, F2, F3, F4, and F5). The study revealed that larger particles consisted of lignin fractions of lower molecular weight and higher phenolic group content (KL-F1 and F2), while smaller but non-uniform particles were produced from fractions of higher molecular weight and lower phenolic group content (KLF4 and F5). Every zeta potential value of the particle exceeded -35 mV. The nanoparticles from raw kraft lignin exhibited no significant cytotoxicity, hemotoxicity, and hypersensitivity. This study revealed that molecular weight and hydroxyl group content in the lignin highly correlated with nanoparticle properties. The present kraft lignin nanoparticles have potential for use in various polymer-based nanotechnology.

An efficient approach for development and optimisation of curcumin-loaded solid lipid nanoparticles' patch for transdermal delivery

This study aimed to develop and optimise a Curcumin-loaded SLNs (C-SLNs) patch through a new approach for transdermal delivery. C-SLNs were optimised through the response surface central composite design using the modified injection method. Optimised C-SLNs were loaded into a polyvinyl alcohol-based patch through the backing membrane method. Compatibility studies (FTIR, XRPD), in vitro release, ex vivo skin permeation, accelerated stability, and evaluation studies of the patch were also performed. Prepared C-SLNs exhibited average particle diameter of 170 ± 2 nm with an encapsulation efficiency of 90 ± 3.5% (w/w) while SEM illustrated spherical shape of particles. In vitro release data ensured a sustained release for up to 72 hours. The enhancement ratio of C-SLNs based patch with permeation enhancer (PE) was high up to 6.5 folds as compared to patch without PE. It is concluded that the modified injection method is simple, economical, and less time consuming for the development of C-SLNs patch for the transdermal route.

Evidence that protein corona reduces the release of antimicrobial peptides from polymeric nanocapsules in milk

The antimicrobial peptide produced by Bacillus velesensis P34 has a broad activity against Gram-positive bacteria, showing potential as natural food preservative. In this work, nanocapsules (NCs) containing the peptide P34 were produced using the polymers poly-ε-caprolactone (PCL) or Eudragit RS-100 (EUD), and their antimicrobial activities were assessed evaluating L. monocytogenes growth in synthetic media, milk and isolated milk proteins. As results, cationic and anionic nanocapsules were obtained, with zeta potential ranging from +15 to +28 mV for EUD and around -19 mV for PCL, and average diameter in the range of 104-130 nm and 224-245 nm, respectively. In the antimicrobial tests, only the P34-EUD NCs presented activity against L. monocytogenes in BHI broth, possibly due to the EUD high swelling and permeability properties, as compared with PCL. In whole and skimmed milk, the P34-EUD NCs caused no inhibition of L. monocytogenes growth, due to a possible interaction of casein proteins with the NCs surface resulting in protein corona formation, which interfered with the antimicrobial peptide release. Therefore, the application of polymeric NCs as antimicrobial delivery systems in foods could be limited by the polymer type, and the adhesion of specific matrix proteins that could form protein corona, reducing the bioactive compound release.

Aminocellulose-grafted-polycaprolactone coated gelatin nanoparticles alleviate inflammation in rheumatoid arthritis: A combinational therapeutic approach

Rheumatoid arthritis (RA) is a chronic autoimmune disorder and serious cause of disability. Despite considerable advances in RA management, challenges like extensive drug metabolism and rapid clearance causes poor bioavailability. Core-shell nanocarriers for co-delivery of glycyrrhizic acid (GA) and budesonide against RA were developed. GA-loaded gelatin nanoparticles (NPs) were synthesized and coated with budesonide encapsulated aminocellulose-grafted polycaprolactone (PCL-AC). GA- and budesonide-loaded PCL-AC-gel NPs had diameter of 200-225 nm. Dual drug-loaded (DDL) NPs reduced joint swelling and erythema in rats while markedly ameliorating bone erosion evidenced by radiological analysis, suppressed collagen destruction, restored synovial tissue, bone and cartilage histoarchitecture with reduced inflammatory cells infiltration. NPs also reduced various inflammatory biomarkers such as TNF-α, IL-1β, COX-2, iNOS. Results of this study suggest that dual NPs exerted superior therapeutic effects in RA compared to free drugs which may be attributed to slow and sustained drug release and NPs' ability to inhibit inflammatory mediators.

Optimization to development of chitosan decorated polycaprolactone nanoparticles for improved ocular delivery of dorzolamide: In vitro, ex vivo and toxicity assessments

The present research work was designed to develop dorzolamide-loaded chitosan-coated polycaprolactone nanoparticles (DRZ-CS-PCL-NPs) for improved ocular delivery. The nanoparticles were prepared by single-step emulsification technique and optimized using the three-factor three-level Box-Behnken design. The optimized DRZ-CS-PCL-NPs prepared with the composition of polycaprolactone (60 mg), chitosan (0.6%) and polyvinyl alcohol (1.5%). The particle size, polydispersity index, zeta potential and encapsulation efficiency of optimized DRZ-CS-PCL-NPs were found to be 192.38 ± 6.42 nm, 0.18 ± 0.04, +5.21 ± 1.24 mV, and 72.48 ± 5.62%, respectively. The dependent and independent response variables showed excellent correlation and signifying the rationality of the optimized DRZ-CS-PCL-NPs. The DRZ release from CS-PCL-NPs showed biphasic behaviour with initial burst release for 2 h after that sustained-release up to 12 h of study. The corneal flux experiment showed many fold enhancement in permeation across goat cornea. DRZ-CS-PCL-NPs exhibited 3.7 fold higher mucoadhesive strength compared to the control. Furthermore, the histopathological assessment and HET-CAM study revealed that the DRZ-CS-PCL-NPs were non-irritant and safe for ocular administration. Therefore, from the present study, it can be concluded that the optimized DRZ-CS-PCL-NPs are safe and have the potential for successful ocular delivery and improved therapeutic efficacy.

Preparation and characterization of a novel thermosensitive and bioadhesive cephalexin nanohydrogel: a promising platform for topical antibacterial delivery

OBJECTIVE

Impetigo is a common and highly contagious bacterial skin infection that mostly affects young children and infants. Herein, we report the development of a thermosensitive and bioadhesive in-situ hydrogel-forming system containing cephalexin-loaded nanoparticles (NPs) suitable for antibacterial drug delivery.

METHODS

The nanohydrogel was formulated using drug-loaded NPs and characterized by its physicochemical characteristics. Antibacterial activities of the cephalexin NPs and nanohydrogel were examined in vitro against Staphylococcus aureus (S. aureus). The ex vivo drug permeation study was performed using rat skin. Finally, this formulation was tested for in vivo antibacterial activity using superficial skin infections in rats.

RESULTS

The mean size and entrapment efficiency of the NPs were found to be 178 nm and 58%, respectively. The transmission electron microscopy analysis verified the formation of spherical NPs. The drug-loaded NPs showed an enhanced eradication effect against S. aureus according to the declined MIC values in comparison with the untreated drug. The ex vivo permeation profile of the cephalexin nanohydrogel showed a slow release pattern for 8 h. When applied on rat skin for 6 days, the nanohydrogel exhibited a superior antibacterial activity with normal hair growth and skin appearance as compared to the plain drug hydrogel.

CONCLUSIONS

These findings suggested that the nanohydrogel could serve as a valuable drug delivery platform against superficial bacterial infections.

PLGA nanoparticle preparations by emulsification and nanoprecipitation techniques: effects of formulation parameters

This study presents the influence of the primary formulation parameters on the formation of poly-dl-lactic-co-glycolic nanoparticles by the emulsification-solvent evaporation, and the nanoprecipitation techniques. In the emulsification-solvent evaporation technique, the polymer and tensoactive concentrations, the organic solvent fraction, and the sonication amplitude effects were analyzed. Similarly, in the nanoprecipitation technique the polymer and tensoactive concentrations, the organic solvent fraction and the injection speed were varied. Additionally, the agitation speed during solvent evaporation, the centrifugation speeds and the use of cryoprotectants in the freeze-drying process were analyzed. Nanoparticles were characterized by dynamic light scattering, laser Doppler electrophoresis, and scanning electron microscopy, and the results were evaluated by statistical analysis. Nanoparticle physicochemical characteristics can be adjusted by varying the formulation parameters to obtain specific sizes and stable nanoparticles. Also, by adjusting these parameters, the nanoparticle preparation processes have the potential to be tuned to yield nanoparticles with specific characteristics while maintaining reproducible results.

PolyBall: A new adsorbent for the efficient removal of endotoxin from biopharmaceuticals

The presence of endotoxin, also known as lipopolysaccharides (LPS), as a side product appears to be a major drawback for the production of certain biomolecules that are essential for research, pharmaceutical, and industrial applications. In the biotechnology industry, gram-negative bacteria (e.g., Escherichia coli) are widely used to produce recombinant products such as proteins, plasmid DNAs and vaccines. These products are contaminated with LPS, which may cause side effects when administered to animals or humans. Purification of LPS often suffers from product loss. For this reason, special attention must be paid when purifying proteins aiming a product as free as possible of LPS with high product recovery. Although there are a number of methods for removing LPS, the question about how LPS removal can be carried out in an efficient and economical way is still one of the most intriguing issues and has no satisfactory solution yet. In this work, polymeric poly-ε-caprolactone (PCL) nanoparticles (NPs) (dP = 780 ± 285 nm) were synthesized at a relatively low cost and demonstrated to possess sufficient binding sites for LPS adsorption and removal with ~100% protein recovery. The PCL NPs removed greater than 90% LPS from protein solutions suspended in water using only one milligram (mg) of NPs, which was equivalent to ~1.5 × 106 endotoxin units (EU) per mg of particle. The LPS removal efficacy increased to a higher level (~100%) when phosphate buffered saline (PBS containing 137 mM NaCl) was used as a protein suspending medium in place of water, reflecting positive effects of increasing ionic strength on LPS binding interactions and adsorption. The results further showed that the PCL NPs not only achieved 100% LPS removal but also ~100% protein recovery for a wide concentration range from 20-1000 μg/ml of protein solutions. The NPs were highly effective in different buffers and pHs. To scale up the process further, PCL NPs were incorporated into a supporting cellulose membrane which promoted LPS adsorption further up to ~100% just by running the LPS-containing water through the membrane under gravity. Its adsorption capacity was 2.8 × 106 mg of PCL NPs, approximately 2 -fold higher than that of NPs alone. This is the first demonstration of endotoxin separation with high protein recovery using polymer NPs and the NP-based portable filters, which provide strong adsorptive interactions for LPS removal from protein solutions. Additional features of these NPs and membranes are biocompatible (environment friendly) recyclable after repeated elution and adsorption with no significant changes in LPS removal efficiencies. The results indicate that PCL NPs are an effective LPS adsorbent in powder and membrane forms, which have great potential to be employed in large-scale applications.

Finding key nanoprecipitation variables for achieving uniform polymeric nanoparticles using neurofuzzy logic technology

Nanoprecipitation is a simple and fast method to produce polymeric nanoparticles (Np); however, most applications require filtration or another separation technique to isolate the nanosuspension from aggregates or polydisperse particle production. In order to avoid variability introduced by these additional steps, we report here a systematic study of the process to yield monomodal and uniform Np production with the nanoprecipitation method. To further identify key variables and their interactions, we used artificial neural networks (ANN) to investigate the multiple variables which influence the process. In this work, a polymethacrylate derivative was used for Np (NpERS) and a database with several formulations and conditions was developed for the ANN model. The resulting ANN model had a high predictability (> 70%) for NpERS characteristics measured (mean size, PDI, zeta potential, and number of particle populations). Moreover, the model identified production variables leading to polymer supersaturation, such as mixing time and turbulence, as key in achieving monomodal and uniform NpERS in one production step. Polymer concentration and type of solvent, modifiers of polymer diffusion and supersaturation, were also shown to control NpERS characteristics. The ANN study allowed the identification of key variables and their interactions and resulted in a predictive model to study the NpERS production by nanoprecipitation. In turn, we have achieved an optimized method to yield uniform NpERS which could pave way for polymeric nanoparticle production methods with potential in biological and drug delivery applications.

Synthesis of polyaniline (PANI) and functionalized polyaniline (F-PANI) nanoparticles with controlled size by solvent displacement method. Application in fluorescence detection and bacteria killing by photothermal effect

Polyaniline nanoparticles (PANI-NPs) were easily obtained applying the solvent displacement method by using N-methylpyrrolidone (NMP) as good solvent and water as poor solvent. Different polymers such as polyvinylpyrrolidone (PVP), chondroitin sulfate (ChS), polyvinyl alcohol (PVA), and polyacrylic acid (PAA) were used as stabilizers. Dynamic light scattering and scanning electron microscopy corroborated the size and morphology of the formed NPs. It was demonstrated that the size of nanoparticles could be controlled by setting the concentration of PANI in NMP, the NMP to water ratio, and the stabilizer's nature. The functionalization and fluorescence of NPs were checked by spectroscopic techniques. Since polyaniline show only weak intrinsic luminescence, fluorescent groups were linked to the polyaniline chains prior to the nanoparticle formation using a linker. Polyaniline chains were functionalized by nucleophilic addition of cysteamine trough the thiol group thereby incorporating pendant primary aliphatic amine groups to the polyaniline backbone. Then, dansyl chloride (DNS-Cl), which could act as an extrinsic chromophore, was conjugated to the amine pendant groups. Later, the functionalized polyaniline was used to produce nanoparticles by solvent displacement. The optical and functional properties of fluorescent nanoparticles (F-PANI-NPs) were determined. F-PANI-NPs in the conductive state (pH < 4) are able to absorb near infrared radiation (NIR) creating a photothermal effect in an aqueous medium. Thus, multifunctional nanoparticles are obtained. The application of NIR on a F-PANI-NPs dispersion in contact with Pseudomonas aeruginosa causes bacterial death. Therefore, the F-PANI-NPs could be tracked and applied to inhibit different diseases caused by pathogenic microorganisms and resistant to antibiotics as well as a new disinfection method to surgical materials.

A review of recent progress in drug and protein encapsulation: Approaches, applications and challenges

Many drugs and proteins formulated for treatment of various diseases are not fully utilised due to environmentally problems such as degradation by enzymes or it being hydrophobic. To counter this problem, the drug and protein of interest are encapsulated by synthetic polymers where they are protected from the environment. This allows the molecule to reach its target safely and maximise its function. In this paper, we will discuss about the different techniques of encapsulation that includes emulsion evaporation, self-emulsifying drug delivery system and supercritical fluid. This will be followed by the drugs and proteins that are commonly encapsulated to counter life-threatening diseases such as cancer and diabetes. A novel method using foam was proposed and will be briefly discussed as it can play a huge role in future developments.