Measurement and evaluation of the effects of pH gradients on the antimicrobial and antivirulence activities of chitosan nanoparticles in Pseudomonas aeruginosa

Objective

The purpose of this study was to study the antimicrobial activity of chitosan nanoparticles (CSNPs) on Pseudomonas aeruginosa with special emphasis on their sensitivity to pH and the effect of pH on their activity.

Functionalized chitosan nanoparticles for cutaneous delivery of a skin whitening agent: an approach to clinically augment the therapeutic efficacy for melasma treatment

The increase in the production of melanin level inside the skin prompts a patient-inconvenient skin color disorder namely; melasma. This arouses the need to develop efficacious treatment modalities, among which are topical nano-delivery systems. This study aimed to formulate functionalized chitosan nanoparticles (CSNPs) in gel form for enhanced topical delivery of alpha-arbutin as a skin whitening agent to treat melasma. Ionic gelation method was employed to prepare α-arbutin-CSNPs utilizing a 2⁴ full factorial design followed by In vitro, Ex vivo and clinical evaluation of the nano-dispersions and their gel forms. Results revealed that the obtained CSNPs were in the nanometer range with positive zeta potential, high entrapment efficiency, good stability characteristics and exhibited sustained release of α-arbutin over 24 h. Ex vivo deposition of CSNPs proved their superiority in accumulating the drug in deep skin layers with no transdermal delivery. DSC and FTIR studies revealed the successful amorphization of α-arbutin into the nanoparticulate system with no interaction between the drug and the carrier system. The comparative split-face clinical study revealed that α-arbutin loaded CSNPs hydrogels showed better therapeutic efficacy compared to the free drug hydrogel in melasma patients, as displayed by the decrease in: modified melasma area and severity index (mMASI) scores, epidermal melanin particle size surface area (MPSA) and the number of epidermal monoclonal mouse anti–melanoma antigen recognized by T cells-1 (MART-1) positive cells which proved that the aforementioned system is a promising modality for melasma treatment.     

Grafting of gallic acid onto chitosan nano particles enhances antioxidant activities in vitro and protects against ochratoxin A toxicity in catfish (Clarias gariepinus)

This study aimed to prepare and characterize enzymatic modified chitosan nanoparticles (CSNPs) with gallic acid (GA) or octyl gallate (OG) to optimize its potential in human application and to evaluate their protective role against ochrtoxin A (OTA) toxicity in catfish. The modified CSNPs have average size around 90 nm with positive charge and high scavenging activity especially GA-CSNPs. In the in vivo study, catfish were divided into 8 groups and treated for 3 weeks as follow: the control group, OTA-treated group (1 mg/kg b.w.), the groups treated with CSNPs, GA-CSNPs or OG-CSNPs (280 mg/kg b.w.) anole or in combination with OTA. Blood, liver and kidney samples were collected for different analyses. OTA induced a significant biochemical disturbances accompanied with oxidative stress in liver and kidney, histological changes and increase DNA fragmentation in the kidney. Co-treatment with OTA plus the different CSNPs resulted in a significant improvement in all tested parameters and histological picture of the kidney. This improvement was more pronounced in the group treated with GA-CSNPs. It could be concluded that grafting of GA or its ester improved the properties of CSNPs. Moreover, GA-CSNPs showed strong scavenging properties than OG-CSNPs due to the blocking of carboxyl groups responsible of the scavenging activity in OG.     

Overcoming the protein corona in chitosan-based nanoparticles

Numerous properties of chitosan have led to its extensive use in the formulation of nanomaterials for drug delivery. However, the cationic surface of chitosan-based nanoparticles adsorbs proteins upon exposure to biological fluids, forming a phenomenon known as ‘protein corona’. This causes several effects such as decreased bioavailability and limited in vivo clinical applications of chitosan nanoparticles. Understanding and overcoming the effects of protein adsorption on chitosan nanoparticles is key for drug delivery purposes. This review focuses on the strategies implemented to increase the stability of chitosan nanoparticles in the systemic circulation by averting the formation of protein corona and the limitations of PEGylation.     

Chitosan Nanoparticles as New Ocular Drug Delivery Systems: in Vitro Stability,in Vivo Fate,and Cellular Toxicity

PURPOSE: To assess the potential of chitosan (CS) nanoparticles for ocular drug delivery by investigating their interaction with the ocular mucosa in vivo and also their toxicity in conjunctival cell cultures. METHODS: Fluorescent (CS-fl) nanoparticles were prepared by ionotropic gelation. The stability of the particles in the presence of lysozyme was investigated by determining the size and their interaction with mucin, by measuring the viscosity of the mucin dispersion. The in vivo interaction of CS-fl nanoparticles with the rabbit cornea and conjunctiva was analyzed by spectrofluorimetry and confocal microscopy. Their potential toxicity was assessed in a human conjunctival cell line by determining cell survival and viability. RESULTS: CS-fl nanoparticles were stable upon incubation with lysozyme and did not affect the viscosity of a mucin dispersion. In vivo studies showed that the amounts of CS-fl in cornea and conjunctiva were significantly higher for CS-fl nanoparticles than for a control CS-fl solution, these amounts being fairly constant for up to 24 h. Confocal studies suggest that nanoparticles penetrate into the corneal and conjunctival epithelia. Cell survival at 24 h after incubation with CS nanoparticles was high and the viability of the recovered cells was near 100%. CONCLUSIONS: CS nanoparticles are promising vehicles for ocular drug delivery.     

Optimised nanoformulation of bromocriptine for direct nose-to-brain delivery: biodistribution,pharmacokinetic and dopamine estimation by ultra-HPLC/mass spectrometry method

Objective: The present work evaluated whether the prepared nanoparticles (NPs) would be able to target the drug to the brain by a non-invasive nasal route enhancing its bioavailability.

Methods: Bromocriptine (BRC) chitosan NPs (CS NPs) were prepared by ionic gelation method. The biodistribution, pharmacokinetic parameters and dopamine concentration was analysed by ultra-HPLC/mass spectrometry method. The histopathological examination in haloperidol-induced Parkinson's disease in mice model following intranasal (i.n.) administration was evaluated.

Results: BRC was found stable in all exposed conditions and the percentage accuracy observed for intra-day and inter-day batch samples ranged from 90.5 to 107% and 95.3 to 98.9% for plasma and brain homogenates, respectively. BRC-loaded CS NPs showed greater retention into the nostrils (42 ± 8.5% radioactivity) for about 4 h, whereas the 44 ± 7.5% could be retained up to 1 h for BRC solution. The brain:blood ratios of 0.96 ± 0.05 > 0.73 ± 0.15 > 0.25 ± 0.05 of BRC-loaded CS NPs (i.n.) > BRC solution (i.n.) > BRC-loaded CS NPs (intravenous), respectively, at 0.5 h indicated direct nose-to-brain transport bypassing blood–brain barrier. BRC-loaded CS NPs administered intranasally showed significantly high dopamine concentration (20.65 ± 1.08 ng/ml) as compared to haloperidol-treated mice (10.94 ± 2.16 ng/ml) (p < 0.05). Histopathology of brain sections showed selective degeneration of the dopaminergic neurons in haloperidol-treated mice which was markedly reverted by BRC-loaded CS NPs.

Conclusion: Nanoparticulate drug delivery system could be potentially used as a nose-to-brain drug delivery carrier for the treatment of Parkinson's disease.     

Sustained release nanoparticulate formulation containing antioxidant-ellagic acid as potential prophylaxis system for oral administration

The aim of the present work was to develop ellagic acid (EA) loaded poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles for oral administration. PLGA nanoparticles were prepared by a method based on the concept of emulsion–diffusion–evaporation by using polyethylene glycol (PEG) 400 as a cosolvent for solubilizing the drug. While developing this method, didodecyldimethylammomium bromide (DMAB) and polyvinyl alcohol (PVA), alone and in combination with chitosan (CS) were employed. DMAB stabilized particles were the smallest of all the formulations with a particle size of 148.5 nm. PVA alone gave particles of 269.7 nm but a blend with CS (80:20) resulted in an increase in particle size (359.6 ± 23.6 nm). Initial release of EA from nanoparticles in pH 7.4 phosphate buffer was rapid, followed by a slower sustained release. Release rates followed the order PVA > PVA–CS > DMAB. Release rate from the PLGA–DMAB particles was slowest, which is attributed to higher hydrophobicity of DMAB as compared to PVA, preventing diffusion of drug out of polymeric matrix. Insolubility of CS at alkaline pH could have retarded the release in case of PVA–CS system. In situ intestinal permeability study of pure drug and the drug encapsulated in nanoparticles prepared using PVA, PVA–CS blend and DMAB as stabilizer in rats showed 66, 75, 73 and 87% permeation, respectively. EA showed good free radical scavenging effect in a yeast cell culture model as well as in a cell free system.     

Natural extracts into chitosan nanocarriers for rosmarinic acid drug delivery

Abstract

Context: Nanotechnology can be applied to deliver and protect antioxidants in order to control the oxidative stress phenomena in several chronic pathologies. Chitosan (CS) nanoparticles are biodegradable carriers that may protect antioxidants with potent biological activity such as rosmarinic acid (RA) in Salvia officinalis (sage) and Satureja montana (savory) extracts for safe and innovative therapies.

Objective: Development and characterization of CS nanoparticles as a stable and protective vehicle to deliver RA for medical applications using natural extracts as sage and savory.

Materials and methods: Antioxidant-CS based nanoparticles were prepared by ionic gelation with sodium tripolyphosphate (TPP), at pH 5.8 with a mass ratio of 7:1 (CS:TPP), with a theoretical antioxidant-CS loading of 40–50%. The nanoparticles were then characterized by different methods such as photon correlation spectroscopy, laser Doppler anemometry, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), high-performance liquid chromatographic (HPLC), association efficiency, and antioxidant activity.

Results and discussion: Individual and small sizing nanoparticles, around 300?nm, were obtained. SEM confirmed smooth and spherical nanoparticles after freeze-drying. No chemical interactions were found between antioxidants and CS, after encapsulation, by DSC and FTIR. The association efficiency was 51.2% for RA (with 40% loading) and 96.1 and 98.2% for sage and savory nanoparticles, respectively (both with 50% loading). Antioxidant activity values were higher than 0.0348?eq [Asc. Ac.] g/L/g extract and 0.4251?µmol/eq Trolox/g extract.

Conclusion: The extracts under study are promising vehicles for RA drug delivery in CS nanocarriers.     

Gold nanoparticles: opportunities and challenges in nanomedicine

Importance of the field: Site-specific drug delivery is an important area of research that is anticipated to increase the efficacy of the drug and reduce potential side effects. Owing to this, substantial work has been done developing non-invasive and targeted tumor treatment with nanoscale metallic particles.

Areas covered in this review: This review focuses on the work done in the last few years developing gold nanoparticles as cancer therapeutics and diagnostic agents. However, there are challenges in using gold nanoparticles as drug delivery systems, such as biodistribution, pharmacokinetics and possible toxicity. Approaches to limit these issues are proposed.

What the reader will gain: Different approaches from several different disciplines are discussed. Potential clinical applications of these engineered nanoparticles are also presented.

Take home message: As a result of their unique size-dependent physicochemical and optical properties, adaptability, subcellular size and biocompatibility, these nanosized carriers offer a suitable means of transporting small molecules as well as biomacromolecules to diseased cells/tissues.     

Antiangiogenic anticancer strategy based on nanoparticulate systems

Introduction: Angiogenesis is a process that provides a blood supply for cancer cells. The discovery that the blockade of this blood supply results in the inhibition of cancer cell growth has been applied in cancer treatment. This antiangiogenic strategy is mainly directed at the inhibition of the binding process between proangiogenic growth factors and their receptors or the inhibition of the activity of proteolytic enzymes of the extracellular matrix. The toxicity of some antiangiogenic agents, such as small-molecule inhibitors, and the instability of antiangiogenic proteins require their formulation in an appropriate delivery system. On the other hand, active drug targeting to selective markers expressed on tumor vasculature could improve antiangiogenic treatment.

Areas covered: The present review focuses on nanoparticulate systems (nanoparticles, liposomes, polymeric micelles, etc.) because their properties could enable both the targeting of endothelial cells and the efficient delivery of antiangiogenic agents. The most important properties of nanoparticles that influence both processes, such as their size, charge and surface modification, are also discussed. Various examples illustrating the targeting ability of nanoparticles are reported, in particular conjugated nanoparticles targeting VEGF and its receptors, fibroblast growth factor and its receptors, EGFRs, MMPs, tubulin function and so on.

Expert opinion: Targeting of nanoparticles (e.g., by tumor-penetrating peptides) allows the co-administration of antiangiogenic and anticancer drugs, facilitates drug penetration into extravascular tumor tissue and improves the therapeutic effect at reduced drug doses.     

Formulation,development and optimization of raloxifene-loaded chitosan nanoparticles for treatment of osteoporosis

Abstract

Context: Osteoporosis (OP) is a disease of skeletal system and is associated with fragility fracture at the hip, spine and wrist. Various drugs have been used to treat OP. One of them is raloxifene hydrochloride (RLX), a second-generation selective estrogen receptor modulator (SERM) approved by the USFDA. RLX possesses only 2% absolute bioavailability (BA) by oral route due to its extensive first-pass metabolism.

Objective: The purpose of the current research work was to develop and evaluate RLX-loaded chitosan nanoparticles (CS-NPs) for treatment of OP with enhanced BA.

Materials and methods: The RLX-loaded CS-NPs were prepared by gelation of CS with tripolyphosphate (TPP) by ionic cross-linking. Formulation was optimized and in vitro drug release and in vivo study were performed.

Results and discussions: CS-NPs were formed by the ionic gelation method. The particle size, entrapment efficiency and loading efficiency varied from 216.65 to 1890?nm, 32.84 to 97.78% and 23.89 to 62.46%, respectively. Release kinetics showed diffusion-controlled and Fickian release pattern. In vivo study indicated higher plasma drug concentration with NPs administered intranasally as compared to drug suspension administered through oral route (p?<?0.05). A significantly higher drug concentration in plasma was achieved in 10?min after nasal administration with respect to oral administration.

Conclusion: The results suggest that RLX-loaded CS-NPs have better BA and would be a promising approach for intranasal (i.n.) delivery of RLX for the treatment of OP.     

Chitosan and Chitosan/Ethylene Oxide-Propylene Oxide Block Copolymer Nanoparticles as Novel Carriers for Proteins and Vaccines

Purpose. The aim of this study was to investigate the interaction between the components of novel chitosan (CS) and CS/ethylene oxide-propylene oxide block copolymer (PEO-PPO) nanoparticles and to evaluate their potential for the association and controlled release of proteins and vaccines. Methods. The presence of PEO-PPO on the surface of the nanoparticles and its interaction with the CS was identified by X-ray photoelectron spectroscopy (XPS). The mechanism of protein association was elucidated using several proteins, bovine serum albumin (BSA), and tetanus and diphtheria toxoids, and varying the formulation conditions (different pH values and concentrations of PEO-PPO), and the stage of protein incorporation into the nanoparticles formation medium. Results. BSA and tetanus and diphtheria toxoids were highly associated with CS nanoparticles partly due to electrostatic interactions between the carboxyl groups of the protein and the amine groups of CS. PEO-PPO also interacted electrostatically with CS, thus competing with the proteins for association with CS nanoparticles. A visible amount of PEO-PPO was projected towards the outer phase of the nanoparticles. Proteins were released from the nanoparticles at an almost constant rate, the intensity of which was closely related to the protein loading. Furthermore, the tetanus vaccine was released in the active form for at least 15 days. Conclusions. CS and CS/PEO-PPO nanoparticles prepared by a very mild ionic crosslinking technique are novel and suitable systems for the entrapment and controlled release of proteins and vaccines.     

Development of gatifloxacin-loaded cationic polymeric nanoparticles for ocular drug delivery

The present investigation aimed at improving the ocular bioavailability of gatifloxacin by prolonging its residence time in the eye and reducing problems associated with the drug re-crystallization after application through incorporation into cationic polymeric nanoparticles. Gatifloxacin-loaded nanoparticles were prepared via the nanoprecipitation and double emulsion techniques. A 50:50 Eudragit® RL and RS mixture was used as cationic polymer with other formulation parameters varied. Prepared nanoparticles were evaluated for size, zeta potential, and drug loading. An optimized formulation was selected and further characterized for in vitro drug release, cytotoxicity, and antimicrobial activity. The double emulsion method produced larger nanoparticles than the nanoprecipitation method (410?nm and 68?nm, respectively). Surfactant choice also affected particle size and zeta potential with Tween 80 producing smaller-sized particles with higher zeta potential than PVA. However, the zeta potential was positive at all experimental conditions investigated. The optimal formulation produced by double emulsion technique and has achieved 46% drug loading. This formulation had optimal physicochemical properties with acceptable cytotoxicity results, and very prolonged release rate. The particles antimicrobial activities of the selected formulation have been tested against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus and showed prolonged antimicrobial effect for gatifloxacin.     

Overcoming the stability,toxicity, and biodegradation challenges of tumor stimuli-responsive inorganic nanoparticles for delivery of cancer therapeutics

ABSTRACT

Introduction: Stimuli-responsive nanomaterials for cancer therapy have attracted much interest recently due to their potential for improving the current standard of care. Different types of inorganic nanoparticles are widely employed for the development of these strategies, but in some cases safety concerns hinder their clinical translation. This review aims to provide an overview of the challenges that inorganic nanoparticles face regarding their stability, toxicity, and biodegradability, as well as the strategies that have been proposed to overcome them.

Areas covered: The available information about the in vitro and in vivo biocompatibility, as well as the biodegradability of the following nanoparticles, is presented and discussed: superparamagnetic iron oxide nanoparticles, gold nanoparticles, graphene and mesoporous nanoparticles made of silicon or silicon oxide. The toxicology of inorganic nanoparticles is greatly affected by many physicochemical parameters, and their surface modification emerges as the main intervention to improve their biocompatibility and tailor their performance for specific biomedical applications.

Expert opinion: Even though many different studies have been performed regarding the biological behavior of inorganic nanoparticles, long-term in vivo data is still scarce, limiting our capacity to evaluate the proposed nanomaterials for clinical use. The role of biodegradability in different therapeutic contexts is also discussed.     

Nanoparticle-based vaginal drug delivery systems for HIV prevention

Importance of the Field: Several strategies are being investigated for the prevention of heterosexual transmission of HIV. Of these, topical vaginal drug delivery systems, microbicides, are being actively pursued. HIV prevention by means of a topical microbicide has several drug delivery challenges. These challenges include the vaginal mucosal barriers and potential degradation of the drugs in the vaginal lumen due to pH and enzymes present. Also, new drugs being evaluated as microbicides have specific mechanisms of action, which in some cases require drug targeting to a specific site of action. Nanoparticles provide a delivery strategy for targeted or controlled delivery to the vagina which can be applied in the field of HIV prevention.

Areas covered in the review: This review summarizes nanoparticulate systems and their use in mucosal delivery to date. The sexual transmission of HIV along with the various targets to prevent transmission are discussed as well as the potential opportunities, challenges and advantages in using a nanoparticle-based approach for microbicidal drug delivery.

What the reader will gain: This review provides a general understanding of vaginal drug delivery, its challenges, and nanoparticulate delivery systems. Additionally, insight will be gained as to the limited existing application of this technology to the field of HIV prevention.

Take home message: To date, few studies have been published that exploit nanoparticle-based microbicidal delivery to the vagina. The use of nanoparticles for vaginal drug delivery provides an approach to overcome the existing barriers to success.     

Amoxicillin,clarithromycin, and omeprazole based targeted nanoparticles for the treatment of H. pylori

The aim of the present study was to develop and characterize targeted sustained release nanoparticles of chitosan–glutamic acid conjugates containing triple therapy for Helicobacter pylori to improve its therapeutic effect and reduce its dose-related side effect. The chitosan–glutamate nanoparticles were prepared by using the ionotropic gelation method. The particle sizes of systems ranged between 550 nm and 900 nm. Percent drug entrapment and release profiles of amoxicillin, clarithromycin, and omeprazole in simulated gastric fluid (pH 1.2) were determined using high-performance liquid chromatography. The maximum % drug entrapment and % yield of formulations were about 60–90% and 73–88%, respectively. The stability of the drugs was assessed in simulated gastric fluid (pH 1.2). In vitro antibacterial efficacy of optimized formulations containing monotherapy and triple therapy on isolated culture of H. pylori was assessed. In vivo clearance study and histopathological study were also carried out on Swiss albino mice to evaluate the efficacy of triple therapy containing targeted nanosystem for the treatment of H. pylori. The proposed delivery system holds promise at optimizing the treatment of H. pylori.     

Characterization and evaluation of chitosan nanoparticles for dopamine brain delivery

The aim of this study was to characterize nanoparticles (NPs) composed of chitosan (CS) and evaluate their potential for brain delivery of the neurotransmitter Dopamine (DA). For this purpose, CS based NPs were incubated with DA at two different concentrations giving rise to nanocarriers denoted as DA/CSNPs (1) and DA/CSNPs (5), respectively. X-ray Photoelectron Spectroscopy (XPS) analysis confirmed that DA was adsorbed onto the external surface of such NPs. The cytotoxic effect of the CSNPs and DA/CSNPs was assessed using the MTT test and it was found that the nanovectors are less cytotoxic than the neurotransmitter DA after 3 h of incubation time. Transport studies across MDCKII-MDR1 cell line showed that DA/CSNPs (5) give rise to a significant transport enhancing effect compared with the control and greater than the corresponding DA/CSNPs (1). Measurement of reactive oxygen species (ROS) suggested a low DA/CSNPs neurotoxicity after 3 h. In vivo brain microdialysis experiments in rat showed that intraperitoneal acute administration of DA/CSNPs (5) (6-12 mg/kg) induced a dose-dependent increase in striatal DA output. Thus, these CS nanoparticles represent an interesting technological platform for DA brain delivery and, hence, may be useful for Parkinson's disease treatment.     

Synthesis and characterization of chitosan quaternary ammonium salt and its application as drug carrier for ribavirin

Abstract

N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) is hydro-soluble chitosan (CS) derivative, which can be obtained by the reaction between epoxypropyl trimethyl ammonium chloride (ETA) and CS. The preparation parameters for the synthesis of HTCC were optimized by orthogonal experimental design. ETA was successfully grafted into the free amino group of CS. Grafting of ETA with CS had great effect on the crystal structure of HTCC, which was confirmed by the XRD results. HTCC displayed higher capability to form nanoparticles by crosslinking with negatively charged sodium tripolyphosphate (TPP). Ribavrin- (RIV-) loaded HTCC nanoparticles were positively charged and were spherical in shape with average particle size of 200?nm. More efficient drug encapsulation efficiency and loading capacity were obtained for HTCC in comparison with CS, however, HTCC nanoparticles displayed faster release rate due to its hydro-soluble properties. The results suggest that HTCC is a promising CS derivative for the encapsulation of hydrophilic drugs in obtaining sustained release of drugs.     

Advancement in multifunctional nanoparticles for the effective treatment of cancer

Introduction: Nanotechnology has gained wider importance for the treatment of various diseases, including cancer. Multifunctional or theranostic agents are emerging as promising therapeutic paradigms, which provide attractive vehicles for both image and therapeutic agents. Nanosystems are capable of diagnosis, specific targeted drug therapy and monitoring therapeutic response. Due to their well-developed surface nature, nanomolecules are easy to anchor with multifunctional groups.

Areas covered: The present review aims to give an extensive account on the progress of multifunctional nanoparticles throughout the blooming research with regards to their clinical application in cancer. This paper discusses graphene, a newly developed multifunctional vehicle in nanotechnology. Furthermore, it focuses on the development of tumor cells, the advantages of novel multifunctional nanoparticles over traditional methods and the use of nanoparticles in cancer therapy. In addition, patents issued by the US office are also included.

Expert opinion: Despite numerous advantages, multifunctional nanoparticles are still at an infancy stage. Many great achievements have been attained in this field to date, but many challenges still remain. A problem that limits the use of multifunctional nanoparticles is toxicity. If this toxicity can be overcome then the advancement in nanocomposite material science will be well on the way to a prospective treatment of cancer.     

The Stenlying Effect of High Hydrostatic Pressure on Thermally and Hydrolytically Labile Nanosized Carriers

Purpose. To investigate whether high hydrostatic pressure (HHP) treatment allows the sterilization of thermosensitive polymer nanoparticle suspensions without jeopardizing their physicochemical integrity. Methods. Application of HHP was explored on a wide variety of thermosensitive poly(cyanoacrylate) nanoparticles, varying by their type (nanospheres or nanocapsules), by their preparation method (nanoprecipitation or emulsion/solvent evaporation), as well as by their surface characteristics. Physicochemical characterization before and after pressurization included turbidimetry, size measurement, zeta potential, scanning electron microscopy and infrared analysis. A sterility test also conducted according to pharmacopoeial requirements on an importantly contaminated nanoparticle suspension. Results. Poly(cyanoacrylate) nanoparticles appeared to be extremely baroresistant. Continuous or oscillatory HHP treatment up to 500 MPa during 30 min induced generally neither physical, nor chemical damage. However, precautions should be taken when surface modifiers are adsorbed onto nanoparticles, as a layer destabilization may occur. Finally, this process allowed the successful inactivation of vegetative bacteria, yeast, and fungi. Conclusions. This work proposes HHP as a new method for polymer drug carriers sterilization, taking into account that further exploration in this area is needed to propose novel protocols for spores inactivation.