PLGA nanoparticle-encapsulated lysostaphin for the treatment of Staphylococcus aureus infections.

Staphylococcus aureus possesses the ability to become pathogenic, leading to severe and life-threatening infections. Its methicillin-resistant variant MRSA has garnered high-priority status due to its increased morbidity and associated mortality. This emphasizes the urgency for novel anti-staphylococcal agents. The bacteriocin lysostaphin stands out for its remarkable bactericidal activity against S. aureus, including MRSA, outperforming conventional antibiotics. However, the clinical application of lysostaphin faces challenges, including enzymatic activity loss under physiological conditions and potential immunogenicity. This study introduces a novel approach by encapsulating lysostaphin within polylactic-co-glycolic acid (PLGA) nanoparticles, a biodegradable copolymer known for its biocompatibility and sustained drug release ability. The study assesses the antimicrobial activity of lysostaphin-loaded PLGA nanoparticles against different S. aureus strains, and we also used GFP-expressing S. aureus for facilitating its traceability in planktonic, biofilm, and intracellular infection models. The results showed the significant reduction in bacteria viability both in planktonic and biofilm states. The in vitro intracellular infection model demonstrated the significantly enhanced efficiency of the developed nanoparticles compared to the treatment with the free bacteriocin. This research presents lysostaphin encapsulation within PLGA nanoparticles and offers promising avenues for enhancing lysostaphin's therapeutic efficacy against S. aureus infections.

Antibody-Functionalized Polymer Nanoparticles for Targeted Antibiotic Delivery in Models of Pathogenic Bacteria Infecting Human Macrophages.

The efficacy of antibody-functionalized poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles (NPs), prepared by nanoprecipitation, carrying rifampicin (RIF) against planktonic, sessile, and intracellular Staphylococcus aureus and Escherichia coli is reported here. A biotinylated anti-S. aureus polyclonal antibody, which binds to structural antigens of the whole bacterium, was functionalized on the surface of RIF-loaded PLGA-based NPs by using the high-affinity avidin-biotin complex. This general strategy allows the binding of commercially available biotinylated antibodies. Coculture models of S. aureus ATCC 25923 and Escherichia coli S17 were used to demonstrate the preferential selectivity of the antibody-functionalized NPs against the Gram-positive bacterium only. At 0.2 µg/mL, complete S. aureus eradication was observed for the antibody-functionalized RIF-loaded NPs, whereas only a 5-log reduction was observed for the nontargeted RIF-loaded NPs. S. aureus is a commensal facultative pathogen having part of its live cycle intracellularly in both phagocytic and nonphagocytic cells. Those intracellular bacterial persisters, named small colony variants, have been postulated as reservoirs of relapsed episodes of infection and consequent treatment failure. At 0.5 µg/mL, the RIF-loaded NPs reduced in 2-log intracellular S. aureus-infecting human macrophages. The ability of those antibody-functionalized nanoparticles to prevent biofilm formation or to reduce the bacterial burden in already-formed mature biofilms is also reported here using S. aureus and E. coli single and cocultured biofilms. In the prevention of S. aureus biofilm formation, the antibody-functionalized NPs exerted a superior inhibition of bacterial growth (up to 2 logs) compared to the nonfunctionalized ones. This study demonstrates the selectivity of the synthesized immunonanoparticles and their antimicrobial efficacy in different scenarios, including planktonic cultures, sessile conditions, and even against intracellular infective pathogens.

Hybrid thermoresponsive nanoparticles containing drug nanocrystals for NIR-triggered remote release.

The on-demand administration of anaesthetic drugs can be a promising alternative for chronic pain management. To further improve the efficacy of drug delivery vectors, high drug loadings combined with a spatiotemporal control on the release can not only relief the pain according to patient's needs, but also improve the drawbacks of conventional burst release delivery systems. In this study, a hybrid nanomaterial was developed by loading bupivacaine nanocrystals (BNCs) into oligo(ethylene glycol) methyl ether methacrylate (OEGMA)-based thermoresponsive nanogels and coupling them to NIR-absorbing biodegradable copper sulphide nanoparticles (CuS NPs). Those CuS NPs were surface modified with polyelectrolytes using layer-by-layer techniques to be efficiently attached to the surface of nanogels by means of supramolecular interactions. The encapsulation of bupivacaine in the form of nanocrystals allowed to achieve CuS@BNC-nanogels having drug loadings as high as 65.5 wt%. The nanocrystals acted as long-lasting drug reservoirs, leading to an elevated localized drug content, which was useful for their application in prolonged pain relief. The CuS@BNC-nanogels exhibited favorable photothermal transducing properties upon NIR-light irradiation. The photothermal effect granted by the CuS NPs triggered the nano-crystallized drug release to be boosted by the collapse of the thermoresponsive nanogels upon heating. Remote control was achieved for on-demand release at a specific time and place, indicating their potential use as an externally activated triggerable drug-delivery system. Furthermore, cell viability tests and flow cytometry analysis were performed showing satisfactory cytocompatibility in the dose-ranging study having a subcytotoxic concentration of 0.05 mg/mL for CuS@BNC-nanogels. This remotely activated nanoplatform is a promising strategy for long-lasting controlled analgesia and a potential alternative for clinical pain management.

Microfluidic Synthesis of Block Copolymer Micelles: Application as Drug Nanocarriers and as Photothermal Transductors When Loading Pd Nanosheets.

The synthesis of polymeric nanoparticles from a block copolymer based on poly(ethylene glycol) and a polymethacrylate containing the nucleobase analog 2,6-diacylaminopyridine is optimized by microfluidics to obtain homogeneous spherical micelles. Loading and delivery properties are studied using naproxen as a model. The incorporation of a Pd precursor in the polymer organic solution fed into the micromixer allows the preparation of Pd(II) precursor-polymer hybrid systems and the subsequent reduction with CO leads to the in situ synthesis of Pd nanosheets inside of the hydrophobic core of the polymeric micelles. This methodology is highly efficient to yield all polymeric nanoparticles loaded with Pd nanosheets as detected by electron microscopy and energy-dispersive X-ray spectroscopy. The cell viability of these Pd nanosheets-containing polymeric nanoparticles is evaluated using five cell lines, showing a high cytocompatibility at the tested concentrations without detrimental effects in cell membrane and nuclei. Furthermore, the use of these hybrid polymeric nanoparticles as photothermal transductors is evaluated using near infrared as irradiation source as well as its application in photothermal therapy using different cell lines demonstrating a high efficiency in all cell cultures.

Customized hybrid and NIR-light triggered thermoresponsive drug delivery microparticles synthetized by photopolymerization in a one-step flow focusing continuous microreactor.

Photopolymerization is a selective technique that takes advantage of light-sensitive molecules to initiate and propagate monomeric structures to render covalently bonded macromolecular materials structures known as polymers. Herein, we present a novel one-step microfluidic synthesis of customized hybrid-thermoresponsive Poly(N-isopropylacrylamide) (PNIPAm) based microparticles (MPs) containing plasmonic hollow gold nanoparticles (HGNPs) and bupivacaine (BVP) used as a model drug. Those hybrid microparticles were prepared using a flow-focusing microreactor coupled to a UV LED device built with a simple outer PTFE tubing and an inner flexible capillary. Different tubing characteristics and flow rate ratios were altered in order to control the size of the resulting microparticles. In addition, components such as monomer, crosslinker and photoinitiator concentrations, as well as LED intensity and irradiation time were tuned to obtain different MPs and their characteristics and polymerization rates were compared by Gel Permeation Chromatography (GPC). Thermoresponsive properties were analyzed and the presence of HGNPs was confirmed in light-activated triggered drug release applications. Bupivacaine loading and release studies were evaluated with the resulting hollow and solid microparticles (which were obtained depending on the polymerization rate used) and their temperature responsiveness was assessed using a NIR laser when HGNPs were present in the constructs. Finally, cytotoxicity studies, cell-cycle arrest and apoptotic induction were carried out to certify their suitability for further biomedical applications to be used as triggerable drug depots.

Triggered drug release from hybrid thermoresponsive nanoparticles using near infrared light.

Aim: Developing hybrid poly(N-isopropylacrylamide)-based nanogels decorated with plasmonic hollow gold nanoparticles for on-demand drug delivery and their physico-chemical characterization, bupivacaine loading and release ability upon light irradiation, and in vitro cell viability. Materials & methods: Hollow gold nanoparticles were prepared by galvanic replacement reaction; poly(N-isopropylacrylamide)-based nanogels were synthesized via precipitation polymerization and their electrostatic coupling was accomplished using poly(allylamine hydrochloride) as cationic polyelectrolyte linker. Results & conclusion: Colloidal stability of the resulted hybrid nanovectors was demonstrated under physiological conditions together with their fast response and excellent heating efficiency after light stimulation, indicating their potential use as triggered drug-delivery vectors. Moreover, their influence on cell metabolism and cell cycle under subcytotoxic doses were studied showing excellent cytocompatibility.

Antimicrobial Wound Dressings against Fluorescent and Methicillin-Sensitive Intracellular Pathogenic Bacteria.

There is limited evidence indicating that drug-eluting dressings are clinically more effective than simple conventional dressings. To shed light on this concern, we have performed evidence-based research to evaluate the antimicrobial action of thymol (THY)-loaded antimicrobial dressings having antibiofilm forming ability, able to eradicate intracellular and extracellular pathogenic bacteria. We have used four different Staphylococcus aureus strains, including the ATCC 25923 strain, the Newman strain (methicillin-sensitive strain, MSSA) expressing the coral green fluorescent protein from the vector pCN47, and two clinical reference strains, Newman-(MSSA) and USA300-(methicillin-resistant strain), as traceable models of pathogenic bacteria commonly infecting skin and soft tissues. Compared to non-loaded dressings, THY-loaded polycaprolactone-based electrospun dressings were also able to eliminate pathogenic bacteria in coculture models based on infected murine macrophages. In addition, by using confocal microscopy and the conventional microdilution plating method, we corroborated the successful ability of THY in preventing also biofilm formation. Herein, we demonstrated that the use of wound dressings loaded with the natural monoterpenoid phenol derivative THY are able to eliminate biofilm formation and intracellular methicillin-sensitive S aureus more efficiently than with their corresponding THY-free counterparts.

Novel intracellular antibiotic delivery system against Staphylococcus aureus: cloxacillin-loaded poly(d,l-lactide-co-glycolide) acid nanoparticles.

Aim: First, to compare in vitro minimum inhibitory concentrations (MIC) of free cloxacillin and cloxacillin-containing nanoparticles (NP) against methicillin-susceptible (MSSA) and resistant Staphylococcus aureus (MRSA) and second, to assess NP antimicrobial activity against intracellular S. aureus. Methods: Poly(d,l-lactide-co-glycolide) acid (PLGA)-NP were loaded with cloxacillin and physico-chemically characterized. MICs were determined for reference strains Newman-(MSSA) and USA300-(MRSA). Murine alveolar macrophages were infected, and bacterial intracellular survival was assessed after incubating with free-cloxacillin or PLGA-cloxacillin-NP. Results & conclusion: For both isolates, MICs for antibiotic-loaded-NP were lower than those obtained with free cloxacillin, indicating that the drug encapsulation improves antimicrobial activity. A sustained antibiotic release was demonstrated when using the PLGA-cloxacillin-NP. When considering the lowest concentrations, the use of drug-loaded NP enabled a higher reduction of intracellular bacterial load.

Electrospun anti-inflammatory patch loaded with essential oils for wound healing.

Wound healing is a complex process that consists of three overlapping phases: inflammation, proliferation, and remodeling. A bacterial infection can increase inflammation and delay this process. Microorganisms are closely related to the innate immune system, such as macrophages and neutrophils, as they can start an inflammatory cascade. Essential oils play an important role in the inhibition and prevention of bacterial growth due to their ability to reduce antimicrobial resistance. The possibility to find a strategy that combines antimicrobial and anti-inflammatory properties is particularly appealing for wound healing. In this work, we showcase a variety of patches based on electrospun polycaprolactone (PCL) nanofibers loaded with natural compounds derived from essential oils, such as thymol (THY) and tyrosol (TYR), to achieve reduced inflammation. In addition, we compared the effect these essential oils have on activated macrophages when incorporated into the PCL patch. Specifically, we demonstrate that PCL-THY resulted in more efficient down-regulation of pro-inflammatory genes related to the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κb) pathway when compared to PCL-TYR and the combination patch containing TYR and THY (i.e., PCL-TYR-THY). Furthermore, PCL-THY displayed low affinity for cell attachment, which may hinder wound adherence and integration. Overall, our results indicate that THY-loaded patches could serve as promising candidates for the fabrication of dressings that incorporate bactericidal and anti-inflammatory properties while simultaneously avoiding the limitations of traditional antibiotic-loaded devices.

Drug-eluting wound dressings having sustained release of antimicrobial compounds.

Wound healing is a complex and costly public health problem that should be timely addressed to achieve a rapid and adequate tissue repair avoiding or even eliminating potential pathogenic infection. Chronic infected non-healing wounds represent a serious concern for health care systems. Efficient wound dressings with tailored therapy having the best response and highest safety margin for the management of chronic non-healing wounds are still needed. The use of novel wound dressing materials has emerged as a promising tool to fulfil these requirements. In this work, asymmetric electrospun polycaprolactone (PCL)-based nanofibers (NFs) were decorated with electrosprayed poly(lactic-co-glycolic acid) microparticles (PLGA MPs) containing the natural antibacterial compound thymol (THY) in order to obtain drug eluting antimicrobial dressings having sustained release. The synthesized dressings successfully inhibited the in vitro growth of Staphylococcus aureus ATCC 25923, showing also at the same doses cytocompatibility on human dermal fibroblasts and keratinocyte cultures after treatment for 24 h, which was not observed when using free thymol. An in vivo murine excisional wound splinting model, followed by the experimental infection of the wounds with S. aureus and their treatment with the synthesized dressings, pointed to the reduction of the bacterial load in wounds after 7 days, though the total elimination of the infection was not reached. The findings indicated the relevance of the direct contact between the dressings and the bacteria, highlighting the need to tune their design considering the wound surface and the nature of the antimicrobial cargo contained.

Composite scaffold obtained by electro-hydrodynamic technique for infection prevention and treatment in bone repair.

Bone infection is a devastating condition resulting from implant or orthopaedic surgery. Therapeutic strategies are extremely complicated and may result in serious side effects or disabilities. The development of enhanced 3D scaffolds, able to promote efficient bone regeneration, combined with targeted antibiotic release to prevent bacterial colonization, is a promising tool for the successful repair of bone defects. Herein, polymeric electrospun scaffolds composed of polycaprolactone (PCL) nanofibres decorated with poly(lactic-co-glycolic acid) (PLGA) particles loaded with rifampicin were fabricated to achieve local and sustained drug release for more efficient prevention and treatment of infection. The release profile showed an initial burst of rifampicin in the first six hours, enabling complete elimination of bacteria. Sustained and long-term release was observed until the end of the experiments (28 days), facilitating a prolonged effect on the inhibition of bacterial growth, which is in agreement with the common knowledge concerning the acidic degradation of the microparticles. In addition, bactericidal effects against gram negative (Escherichia coli) and gram positive (Staphylococcus aureus) bacteria were demonstrated at concentrations of released rifampicin up to 58 ppm after 24 h, with greater efficacy against S. aureus (13 ppm vs 58 ppm for E. coli). Cell morphology and cytocompatibility studies highlighted the suitability of the fabricated scaffolds to support cell growth, as well as their promising clinical application for bone regeneration combined with prevention or treatment of bacterial infection.

Electrospun asymmetric membranes for wound dressing applications.

To accomplish a rapid wound healing it is necessary to develop an asymmetric membrane with interconnected pores consisting of a top layer that prevents rapid dehydration of the wound and bacteria penetration and a sub-layer with high absorption capacity and bactericidal properties. Polycaprolactone (PCL)/polyvinyl acetate (PVAc) asymmetric membranes loaded with the bactericidal monoterpene carvacrol (CRV) were synthesized and characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Mechanical properties in dry and wet conditions and fluid handling behavior were also assessed. In addition, biological studies regarding their bactericidal effects, cytocompatibility and wound closure properties were also developed. Loading efficiencies of 40-50% were achieved in the prepared samples and 85-100% of the loaded CRV was released in simulated wound pH evolution medium. The significant inhibition of Gram negative (Escherichia coli S17) and Gram positive (Staphylococcus aureus ATCC 25923) bacteria growth clearly showed the suitability of the fabricated membranes for wound healing applications. Furthermore, cytocompatibility of the loaded membranes was demonstrated both in 2D and 3D human dermal fibroblast cultures, as well as cell migration was not impaired by released carvacrol from the membranes. These results highlight the potential of these polymeric electrospun membranes for wound healing.

Matryoshka-type gastro-resistant microparticles for the oral treatment of Mycobacterium tuberculosis.

AIM: Production of Matryoshka-type gastroresistant microparticles containing antibiotic-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (NP) against Mycobacterium tuberculosis. MATERIALS & METHODS: The emulsification and evaporation methods were followed for the synthesis of PLGA-NPs and methacrylic acid-ethyl acrylate-based coatings to protect rifampicin from degradation under simulated gastric conditions. RESULTS & CONCLUSION: The inner antibiotic-loaded NPs here reported can be released under simulated intestinal conditions whereas their coating protects them from degradation under simulated gastric conditions. The encapsulation does not hinder the antituberculosis action of the encapsulated antibiotic rifampicin. A sustained antibiotic release could be obtained when using the drug-loaded encapsulated NPs. Compared with the administration of the free drug, a more effective elimination of M. tuberculosis was observed when applying the NPs against infected macrophages. The antibiotic-loaded PLGA-NPs were also able to cross an in vitro model of intestinal barrier.

Polymeric electrospun scaffolds for bone morphogenetic protein 2 delivery in bone tissue engineering.

HYPOTHESIS: The development of novel scaffolds based on biocompatible polymers is of great interest in the field of bone repair for fabrication of biodegradable scaffolds that mimic the extracellular matrix and have osteoconductive and osteoinductive properties for enhanced bone regeneration. EXPERIMENTS: Polycaprolactone (PCL) and polycaprolactone/polyvinyl acetate (PCL/PVAc) core-shell fibers were synthesised and decorated with poly(lactic-co-glycolic acid) [PLGA] particles loaded with bone morphogenetic protein 2 (BMP2) by simultaneous electrospinning and electrospraying. Hydroxyapatite nanorods (HAn) were loaded into the core of fibers. The obtained scaffolds were characterised by scanning and transmission electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The in vitro potential of these materials for bone regeneration was assessed in biodegradation assays, osteoblast viability assays, and analyses of expression of specific bone markers, such as alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). FINDINGS: PLGA particles were homogeneously distributed in the entire fibre mat. The growth factor load was 1.2-1.7 µg/g of the scaffold whereas the HAn load was in the 8.8-12.6 wt% range. These scaffolds were able to support and enhance cell growth and proliferation facilitating the expression of osteogenic and osteoconductive markers (OCN and OPN). These observations underline the great importance of the presence of BMP2 in scaffolds for bone remodelling as well as the good potential of the newly developed scaffolds for clinical use in tissue engineering.

Enzyme structure and function protection from gastrointestinal degradation using enteric coatings.

Bovine Serum Albumin (BSA) and Horseradish Peroxidase (HRP) have been encapsulated within microparticulated matrices composed of Eudragit RS100 by the water-in-oil-in-water double emulsion solvent evaporation method. Good encapsulation efficiencies were achieved for BSA and HRP, 88.4 and 95.8%, respectively. The stability of the loaded proteins was confirmed by using circular dichroism and fluorescence. The gastroresistance of the protein-loaded microparticles was evaluated under simulated gastric conditions demonstrating the preservation of the structural integrity of the proteins loaded inside the particles. The enzymatic activity of HRP after being released from the enteric microparticles was evaluated by using the peroxidase substrate, revealing that the released enzyme preserved its 100% function. The high drug loadings achieved, reduced cytotoxicity and efficient gastric protection point out towards the potential use of those carriers as oral delivery vectors of therapeutic proteins offering a more controlled targeted release in specific sites of the intestine and an enhanced gastrointestinal absorption.

Chitosan-based coatings in the prevention of intravascular catheter-associated infections.

Central venous access devices play an important role in patients with prolonged intravenous administration requirements. In the last years, the coating of these devices with bactericidal compounds has emerged as a potential tool to prevent bacterial colonization. Our study describes the modification of 3D-printed reservoirs and silicone-based catheters, mimicking central venous access devices, through different approaches including their coating with the well known biocompatible and bactericidal polymer chitosan, with the anionic polysaccharide alginate; also, plasma treated surfaces were included in the study to promote polymer adhesion. The evaluation of the antimicrobial action of those surface modifications compared to that exerted by a model antibiotic (ciprofloxacin) adsorbed on the surface of the devices was carried out. Surface characterization was developed by different methodologies and the bactericidal effects of the different coatings were assayed in an in vitro model of Staphylococcus aureus infection. Our results showed a significant reduction in the reservoir roughness (≤73%) after coating though no changes were observed for coated catheters which was also confirmed by scanning electron microscopy, pointing to the importance of the surface device topography for the successful attachment of the coating and for the subsequent development of bactericidal effects. Furthermore, the single presence of chitosan on the reservoirs was enough to fully inhibit bacterial growth exerting the same efficiency as that showed by the model antibiotic. Importantly, chitosan coating showed low cytotoxicity against human keratinocytes, human lung adenocarcinoma epithelial cells, and murine colon carcinoma cells displaying viability percentages in the range of the control samples (>95%). Chitosan-based coatings are proposed as an effective and promising solution in the prevention of microbial infections associated to medical devices.

Antibiotic-eluting orthopedic device to prevent early implant associated infections: Efficacy, biocompatibility and biodistribution studies in an ovine model.

Infection of orthopedic devices is a major complication in the postsurgical period generating important health issues and economic consequences. Prevention strategies could be based on local release of antibiotics from the orthopedic device itself to avoid adhesion and growth of bacteria. The purpose of this work is to demonstrate the efficiency to prevent these infections by a cefazolin-eluting, perforated stainless steel implant in an in vivo ovine model. The device was placed in the tibia of sheep, one group receiving cefazolin-loaded implants whereas the control group received empty implants. All implants were experimentally infected by direct inoculation of Staphylococcus aureus ATCC 6538. In vitro cytotoxicological studies were also performed to check the effect of antibiotic on cell viability, integrity, and cycle. Results showed that sheep receiving cefazolin-loaded devices were able to avoid implant-associated infections, with normal tissue healing process. The antibiotic release followed a local concentric pattern as demonstrated by high-performance liquid chromatography detection in tissues. The in vitro results indicate the lack of relevant cytotoxic effects for the maximum antibiotic concentration released by the device. These results demonstrate the efficiency and safety of cefazolin-eluting implants in an ovine model to prevent early postsurgical infections of orthopedic devices. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1976-1986, 2018.

Inhibitory effects of different antioxidants on hyaluronan depolymerization.

Hyaluronan (HA) was depolymerized by hydroxyl radicals generated from hydrogen peroxide and cupric ions. Inhibition of HA degradation by four well-known antioxidants was investigated, as HA can scavenge reactive oxygen species (ROS). Change in hyaluronan molecular weight was observed by size-exclusion chromatography. Inhibition of HA degradation was estimated from the retention times observed. It was found that HA degradation was inhibited in a clearly concentration-dependent manner by mannitol, thiourea and vinpocetine. Propofol also inhibited the depolymerization, but its concentration-dependent effect was not so clear. The antioxidant concentrations at which HA degradation was decreased by 50% were 42 microM for thiourea; 1.35 microM for vinpocetine; and 0.39 microM for propofol. A concentration of 26.51 mM of mannitol was needed to attain the same inhibitory effect. Although many factors are involved in a therapeutic response, the results obtained in this study support the idea that HA may be protected from ROS attack by the concomitant use of well-known antioxidants.

Laser-treated electrospun fibers loaded with nano-hydroxyapatite for bone tissue engineering.

Core-shell polycaprolactone/polycaprolactone (PCL/PCL) and polycaprolactone/polyvinyl acetate (PCL/PVAc) electrospun fibers loaded with synthesized nanohydroxyapatite (HAn) were lased treated to create microporosity. The prepared materials were characterized by XRD, FTIR, TEM and SEM. Uniform and randomly oriented beadless fibrous structures were obtained in all cases. Fibers diameters were in the 150-300nm range. Needle-like HAn nanoparticles with mean diameters of 20nm and length of approximately 150nm were mostly encase inside the fibers. Laser treated materials present micropores with diameters in the range 70-120µm for PCL-HAn/PCL fibers and in the 50-90µm range for PCL-HAn/PVAC material. Only samples containing HAn presented bioactivity after incubation during 30days in simulated body fluid. All scaffolds presented high viability, very low mortality, and human osteoblast proliferation. Biocompatibility was increased by laser treatment due to the surface and porosity modification.