Controlled-release formulation of perindopril erbumine loaded PEG-coated magnetite nanoparticles for biomedical applications

Iron oxide nanoparticles (FNPs) were synthesized due to low toxicity and their ability to immobilize biological materials on their surfaces by the coprecipitation of iron salts in ammonia hydroxide followed by coating it with polyethylene glycol (PEG) to minimize the aggregation of iron oxide nanoparticles and enhance the effect of nanoparticles for biological applications. Then, the FNPs–PEG was loaded with perindopril erbumine (PE), an antihypertensive compound to form a new nanocomposite (FPEGPE). Transmission electron microscopy results showed that there are no significant differences between the sizes of FNPs and FPEGPE nanocomposite. The existence of PEG–PE was supported by the FTIR and TGA analyses. The PE loading (10.3 %) and the release profiles from FPEGPE nanocomposite were estimated using ultraviolet–visible spectroscopy which showed that up to 60.8 and 83.1 % of the adsorbed drug was released in 4223 and 1231 min at pH 7.4 and 4.8, respectively. However, the release of PE was completed very fast from a physical mixture (FNPs–PEG–PE) after 5 and 7 min at pH 4.8 and 7.4, respectively, which reveals that the release of PE from the physical mixture is not in the sustained-release manner. Cytotoxicity study showed that free PE presented slightly higher toxicity than the FNPs and FPEGPE nanocomposite. Therefore, the decrease toxicity against mouse normal fibroblast (3T3) cell lines prospective of this nanocomposite together with controlled-release behavior provided evidence of the possible beneficial biological activities of this new nanocomposite for nanopharmaceutical applications for both oral and non-oral routes.     

Nanostructured medical device coatings based on self-assembled poly(lactic-co-glycolic acid) nanoparticles

Here we present a new method for providing nanostructured drug-loaded polymer films which enable control of film surface morphology and delivery of therapeutic agents. Silicon wafers were employed as models for implanted biomaterials and poly(lactic-co-glycolic acid) (PLGA) nanoparticles were assembled onto the silicon surface by electrostatic interaction. Monolayers of the PLGA particles were deposited onto the silicon surface upon incubation in an aqueous particle suspension. Particle density and surface coverage of the silicon wafers were varied by altering particle concentration, incubation time in nanoparticle suspension and ionic strength of the suspension. Dye loaded nanoparticles were prepared and assembled to silicon surface to form nanoparticle films. Fluorescence intensity measurements showed diffusion-controlled release of the dye over two weeks and atomic force microscopy (AFM) analysis revealed that these particles remained attached to the surface during the incubation time. This work suggests that coating implants with PLGA nanoparticles is a versatile technique which allows drug release from the implant surface and modulation of surface morphology.     

OX26 modified hyperbranched polyglycerol-conjugated poly(lactic-co-glycolic acid) nanoparticles: synthesis, characterization and evaluation of its brain delivery ability

A novel nanoparticles-based brain drug delivery system made of hyperbranched polyglycerol-conjugated poly(lactic-co-glycolic acid) which was surface functionalized with transferrin antibody (OX26) was prepared. Hyperbranched polyglycerol-conjugated poly(lactic-co-glycolic acid) was synthesized, characterized and applied to prepare nanoparticles by means of double emulsion solvent evaporation technique. Transmission electron micrograph and dynamic light scattering showed that nanoparticles had a round and regular shape with a mean diameter of 170 ± 20 nm. Surface chemical composition was detected by X-ray photoelectron spectroscopy. Endomorphins, as a model drug, was encapsulated in the nanoparticles. In vitro drug release study showed that endomorphins was released continuously for 72 h. Cellular uptake study showed that the uptake of nanoparticles by the brain microvascular endothelial cells was both time- and concentration-dependant. Further uptake inhibition study indicated that the uptake of nanoparticles was via a caveolae-mediated endocytic pathway. In vivo endomorphins brain delivery ability was evaluated based upon the rat model of chronic constriction injury of sciatic nerve. OX26 modified nanoparticles had achieved better analgesic effects, compared with other groups. Thus, OX26 modified hyperbranched polyglycerol-conjugated poly(lactic-co-glycolic acid) nanoparticles may be a promising brain drug delivery carrier.     

Development of poly (lactic-co-glycolic acid)-collagen scaffolds for tissue engineering

Collagen as an important extra-cellular matrix (ECM) in many tissues is weakly antigenic and the structure of collagen sponges is highly porous with interconnected pores effective for cell infiltration and mass transfer of oxygen and nutrients. Its application as a scaffold is limited by poor mechanical strength and rapid biodegradation. In this paper, we attempt to graft hydrolyzed PLGA fiber surfaces with collagen by N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDC) in combination with N-hydroxysuccinimide (NHS), and then embed these collagen-grafted PLGA fibers in collagen sponge to form a hybrid PLGA-collagen scaffold. For further stability, we cross-linked the collagen in the scaffold and used it in rat liver cell cultivation. The scaffold was characterized by mechanical micro-tester, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Results showed that (1) the scaffolds exhibited isotropic and interconnected porous structure; (2) the compression modulus of this scaffold was enhanced 50 fold compared to the collagen scaffolds. The cell attachment and cytotoxicity of this scaffold were studied. Cell attachment was improved remarkably and the cytotoxicity of the hybrid PLGA-collagen scaffold was lower than that of the un-grafted PLGA-collagen scaffolds using alamarBlue™ assay normalized to the DNA content in each scaffold. This new hybrid scaffold has potential applications for tissue engineering.     

In vitro degradation of poly(ester-urethanes) for biomedical applications

Degradation studies on a series of polyesterurethanes having different compositions of hard and soft blocks have been performed utilizing an accelerated test method. Degradation was followed by titrimetry, mass loss, mechanical properties and infrared spectroscopy. As the number of methylene groups present within the polyester moiety was increased, the resistance to degradation also increased. The presence of an aromatic component in the hard block reduced the rate of hydrolysis but the degradation in mechanical properties was accelerated.     

Encapsulation of superparamagnetic iron oxide nanoparticles in poly-(lactide-co-glycolic acid) microspheres for biomedical applications

Magnetic microspheres were prepared using a single step coaxial electrohydrodynamic atomization technique at ambient temperature and pressure, with poly(lactic-co-glycolic acid) as the coating and iron oxide (Fe₃O₄) nanoparticles dispersed in polyethylene glycol as the encapsulated material. The morphology and particle size distributions of the prepared magnetic microspheres were investigated by scanning electron microscopy. The particles were spherical with mean diameters ranging from ~ 2 μm to 18 μm, depending on the combination of processing parameters (flow rate and applied voltage). Analysis by infrared spectroscopy and focused ion-beam sectioning confirmed incorporation of iron oxide nanoparticles into the microspheres and the prepared samples were shown to be responsive to an applied magnetic field. This study demonstrates a convenient method for the preparation of nanoparticle loaded microspheres, which could be used potentially as transverse relaxation contrast agents in magnetic resonance imaging, as well as for magnetically guided drug delivery.     

Effects of poly(lactic-co-glycolic acid) on preparation and characteristics of plasmid DNA-loaded solid lipid nanoparticles

Poly(lactic-co-glycolic acid) (PLGA) was used as a polymeric emulsifier to encapsulate plasmid DNA into hydrogenated castor oil (HCO)-solid lipid nanoparticles (SLN) by w/o/w double emulsion and solvent evaporation techniques. The effects of PLGA on the preparation, characteristics and transfection efficiency of DNA-loaded SLN were studied. The results showed that PLGA was essential to form the primary w/o emulsion and the stability of the emulsion was enhanced with the increase of PLGA content. DNA-loaded SLN were spherical with smooth surfaces. The SLN had a negative charge in weak acid and alkaline environment but acquired a positive charge in acidic pH and the cationisation capacity of the SLN increased with the increase of PLGA/HCO ratio. Agarose gel electrophoresis demonstrated that the majority of the DNA maintained its structural integrity after preparation and being extracted or released from DNA-loaded SLN. When PLGA/HCO ratio increased from 5 to 15%, the encapsulation efficiency, loading capacity and transfection efficiency of the nanoparticles increased significantly, whereas the changes of particle size and polydispersity index were insignificant. Cytotoxicity study in cell culture demonstrated that the SLN was not toxic.     

Facile one-pot synthesis of iron oxide nanoparticles cross-linked magnetic poly(vinyl alcohol) gel beads for drug delivery

In this paper, a facile one-pot strategy for scalable synthesis of robust magnetic poly(vinyl alcohol) (mPVA) gel beads is developed. Through dropwise addition of mixed aqueous solution of iron salts and PVA solution into alkaline (e.g., ammonia, NaOH, and KOH) solution, mPVA gel beads with uniform size and excellent superparamagnetic property can be fabricated based on the simultaneous formation of magnetic iron oxide nanoparticles (MIONs) and cross-link of PVA chains. Moreover, this approach can be extended to prepare dual- or multiresponsive gel beads through simply adding functional fillers into PVA solution (e.g., mPVA-PNIPAM gel beads that possess both magnetic and temperature responsibilities can be readily prepared by adding temperature responsive poly(N-isopropylacrylamide) (PNIPAM) into PVA solution). It is found that that the obtained mPVA gel beads exhibit high drug loading level (e.g., above 70%) after the treatment of freezing-thawing. Drug release experiments reveal that the drug release rate and amount of the mPVA gel beads can be tuned by operating the external magnetic field and adjusting the concentration of iron oxide nanoparticles and temperature (for mPVA-PNIPAM gel beads). The present work is of interest for opening up enormous opportunities to make full use of magnetic gel beads in drug delivery and other applications, because of their facile availability, cost-effective productivity, and tunable drug release performance.     

Mucoadhesive plasticized system of branched poly(lactic-co-glycolic acid) with aciclovir

Commercially available antibacterial semisolid preparations intended for topical application provide only short-term drug release. A sustained kinetics is possible by exploitation of a biodegradable polymer carrier. The purpose of this work is to formulate a mucoadhesive system with aciclovir (ACV) based on a solid molecular dispersion of this drug in poly(lactic-co-glycolic acid) branched on tripenterythritol (PLGA/T). The ACV incorporation into PLGA/T was carried out either by solvent method, or melting method, or plasticization method using various plasticizers. The drug–polymer miscibility, plasticizer efficiency and content of residual solvent were found out employing DSC. Viscosity was measured at the shear rate range from 0.10 to 10.00?s^?1 at three temperatures and data were analyzed by Newtonian model. The mucoadhesive properties were ascertained in the tensile test on a mucin substrate. The amount of ACV released was carried out in a wash-off dissolution test. The DSC results indicate a transformation of crystalline form of ACV into an amorphous dissolved in branched polyester carrier, and absence of methyl formate residuals in formulation. All the tested plasticizers are efficient at T_g depression and viscosity decrease. The non-conventional ethyl pyruvate possessing supportive anti-inflammatory activity was evaluated as the most suitable plasticizer. The ACV release was strongly dependent on the ethyl pyruvate concentration and lasted from 1 to 10 days. The formulated PLGA/T system with ACV exhibits increased adhesion to mucosal hydrophilic surfaces and prolonged ACV release controllable by degradation process and viscosity parameters.     

Polyurethane/poly(hydroxyethyl methacrylate) semi-interpenetrating polymer networks for biomedical applications

The thermodynamic miscibility, morphology, phase distribution, mechanical properties, surface properties, water sorption, bacterial adhesion and cytotoxicity of semi-interpenetrating polymer networks (semi-IPNs) based on crosslinked polyurethane (PU) and poly(hydroxyethylmethacrylate) (PHEMA) were studied to give an insight into their structure and properties. The free energies of mixing of the two polymers in semi-IPNs have been determined and it was shown that the values are positive and depend on the amount of PHEMA. This demonstrates that the components are immiscible, the extent of which is dependent upon variations in composition. The morphology of the semi-IPNs was analyzed with scanning electron microscopy and tapping mode atomic force microscopy (TMAFM). The micrographs of the semi-IPNs and TMAFM phase images indicated that distinct phase separation at the nanometer scale is observed. The mechanical properties reflect the changes in structure of semi-IPNs with composition. The stress at break increases from 3.4 MPa to 23.9 MPa, and the Young’s modulus from 12.7 MPa up to 658.5 MPa with increasing amounts of PHEMA, but strain at break has a maximum at 40.4% PHEMA. The bacterial adhesion and cytotoxicity data suggest that semi-IPNs with PHEMA content above 22% may be used for biomedical material applications.     

Block copolymers of L-lactide and poly(ethylene glycol) for biomedical applications

Poly (L-lactide)-poly (oxyethylene)-poly (L-lactide) block copolymers obtained in bulk, by a ring opening mechanism, from poly (ethylene glycol)s (PEG)s and L-lactide (LA), at 120–140°C, in the absence of added catalysts are described. By using PEGs with different molecular masses, 3000 and 35000, respectively, and varying the initial molar ratio LA to PEG, two series of copolymers with different molecular masses, relative length of blocks and hydrophilicity were obtained. Physico-chemical characterization of the copolymers had been previously performed. The morphological characteristics of the copolymers were investigated by means of X-ray diffractometry, optical and scanning electron microscopy. The biological properties of the materials were determined by evaluating their cytotoxicity, cytocompatibility, hemocompatibility and degradability using different standard tests. The results obtained indicate that the block copolymers synthesized may be useful for biomedical applications, in particular as resorbable drug vehicles. The materials are brittle and their mechanical properties are not appropriate for implant devices.     

Covalently linking poly(lactic-co-glycolic acid) nanoparticles to microbubbles before intravenous injection improves their ultrasound-targeted delivery to skeletal muscle

Intravenously injected nanoparticles can be delivered to skeletal muscle through capillary pores created by the activation of microbubbles with ultrasound; however, strategies that utilize coinjections of free microbubbles and nanoparticles are limited by nanoparticle dilution in the bloodstream. Here, improvement in the delivery of fluorescently labeled ≈150 nm poly(lactic-co-glycolic acid) nanoparticles to skeletal muscle is attempted by covalently linking them to albumin-shelled microbubbles in a composite agent formulation. Studies are performed using an experimental model of peripheral arterial disease, wherein the right and left femoral arteries of BalbC mice are surgically ligated. Four days after arterial ligation, composite agents, coinjected microbubbles and nanoparticles, or nanoparticles alone are administered intravenously and 1 MHz pulsed ultrasound was applied to the left hindlimb. Nanoparticle delivery was assessed at 0, 1, 4, and 24 h post-treatment by fluorescence-mediated tomography. Within the coinjection group, both microbubbles and ultrasound are found to be required for nanoparticle delivery to skeletal muscle. Within the composite agent group, nanoparticle delivery is found to be enhanced 8- to 18-fold over 'no ultrasound' controls, depending on the time of measurement. A maximum of 7.2% of the initial nanoparticle dose per gram of tissue was delivered at 1 hr in the composite agent group, which was significantly greater than in the coinjection group (3.6%). It is concluded that covalently linking 150 nm-diameter poly(lactic-co-glycolic acid) nanoparticles to microbubbles before intravenous injection does improve their delivery to skeletal muscle.     

Facile one-pot synthesis of near-infrared luminescent gold nanoparticles for sensing copper (II)

Novel near-infrared luminescent gold nanoparticles (NIRL-AuNPs) were synthesized by a simple, rapid and one-pot procedure. The driving force for the formation of these NIRL-AuNPs was attributed to the heat-assisted reduction of a gold(I)-thiol complex. These gold nanoparticles were characterized by TEM, DLS, FT-IR and XPS. Luminescence studies indicated that these NIRL-AuNPs exhibited strong emission with peak maximum at 810 nm, microsecond-range photoluminescence lifetime, large Stokes shifts (>400 nm) and stabilities towards photobleaching and chemical oxidation. The sensing application for Cu(2+) ions of these NIRL-AuNPs was demonstrated. These as-synthesized gold nanoparticles will provide a new NIRL nanomaterial for in vitro and in vivo applications.     

Macroporous interpenetrating cryogel network of poly(acrylonitrile) and gelatin for biomedical applications

Cryogels are supermacroporous gel network formed by cryogelation of appropriate monomers or polymeric precursors at subzero temperature. The beneficial feature of this system is a unique combination of high porosity with adequate mechanical strength and osmotic stability, due to which they are being envisaged as potential scaffold material for various biomedical applications. One of the important aspect of cryogel is simple approach by which they can be synthesized and use of aqueous solvent for their synthesis which make them suitable for different biological applications. Various modifications of the cryogels have been sought which involves coupling of various ligands to its surfaces, grafting of polymer chain to cryogel surface or interpenetrating networks of two or more polymers to form a cryogel which provides diversity of its applications. In the following work we have synthesized full interpenetrating network of polyacrylonitrile (PAN)-gelatin with varied gelatin concentration. The PAN-gelatin cryogel interpenetrating network is macroporous in nature and has high percentage swelling equilibrium in the range of 862-1,200 with a flow rate greater than 10 ml/min, which characterizes the interconnectivity of pores and convective flow within the network. PAN-gelatin interpenetrating cryogel network has good mechanical stability as determined by Young's modulus which varies from 123 kPa to 819 kPa depending upon the polymer concentration. Moreover they are shown to be biocompatible and support cell growth within the scaffolds.     

Macroporous interpenetrating cryogel network of poly(acrylonitrile) and gelatin for biomedical applications

Cryogels are supermacroporous gel network formed by cryogelation of appropriate monomers or polymeric precursors at subzero temperature. The beneficial feature of this system is a unique combination of high porosity with adequate mechanical strength and osmotic stability, due to which they are being envisaged as potential scaffold material for various biomedical applications. One of the important aspect of cryogel is simple approach by which they can be synthesized and use of aqueous solvent for their synthesis which make them suitable for different biological applications. Various modifications of the cryogels have been sought which involves coupling of various ligands to its surfaces, grafting of polymer chain to cryogel surface or interpenetrating networks of two or more polymers to form a cryogel which provides diversity of its applications. In the following work we have synthesized full interpenetrating network of polyacrylonitrile (PAN)-gelatin with varied gelatin concentration. The PAN-gelatin cryogel interpenetrating network is macroporous in nature and has high percentage swelling equlibirium in the range of 862–1,200 with a flow rate greater than 10 ml/min, which characterizes the interconnectivity of pores and convective flow within the network. PAN-gelatin interpenetrating cryogel network has good mechanical stability as determined by Young’s modulus which varies from 123 kPa to 819 kPa depending upon the polymer concentration. Moreover they are shown to be biocompatible and support cell growth within the scaffolds.     

Application of rotatable central composite design in the preparation and optimization of poly(lactic-co-glycolic acid) nanoparticles for controlled delivery of paclitaxel

Context: Polymeric carrier systems of paclitaxel (PCT) offer advantages over only available formulation Taxol® in terms of enhancing therapeutic efficacy and eliminating adverse effects. Objective: The objective of the present study was to prepare poly (lactic-co-glycolic acid) nanoparticles containing PCT using emulsion solvent evaporation technique. Methods: Critical factors involved in the processing method were identified and optimized by scientific, efficient rotatable central composite design aiming at low mean particle size and high entrapment efficiency. Twenty different experiments were designed and each formulation was evaluated for mean particle size and entrapment efficiency. The optimized formulation was evaluated for in vitro drug release, and absorption characteristics were studied using in situ rat intestinal permeability study. Results: Amount of polymer and duration of ultrasonication were found to have significant effect on mean particle size and entrapment efficiency. First-order interactions of amount of miglyol with amount of polymer were significant in case of mean particle size, whereas second-order interactions of polymer were significant in mean particle size and entrapment efficiency. The developed quadratic model showed high correlation (R² > 0.85) between predicted response and studied factors. The optimized formulation had low mean particle size (231.68 nm) and high entrapment efficiency (95.18%) with 4.88% drug content. The optimized formulation showed controlled release of PCT for more than 72 hours. In situ absorption study showed faster and enhanced extent of absorption of PCT from nanoparticles compared to pure drug. Conclusion: The poly (lactic-co-glycolic acid) nanoparticles containing PCT may be of clinical importance in enhancing its oral bioavailability.     

Fungal xylanases‐mediated synthesis of silver nanoparticles for catalytic and biomedical applications

Green synthesis of nanoparticles has fuelled the use of biomaterials to synthesise a variety of metallic nanoparticles. The current study investigates the use of xylanases of Aspergillus niger L3 (NEA) and Trichoderma longibrachiatum L2 (TEA) to synthesise silver nanoparticles (AgNPs). Characterisation of AgNPs was carried out using UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy, while their effectiveness as antimicrobial, antioxidant, catalytic, anticoagulant, and thrombolytic agents were determined. The colloidal AgNPs was brownish with surface plasmon resonance at 402.5 and 410 nm for NEA‐AgNPs and TEA‐AgNPs, respectively; while FTIR indicated that protein molecules were responsible for the capping and stabilisation of the nanoparticles. The spherical nanoparticles had size of 15.21–77.49 nm. The nanoparticles significantly inhibited the growth of tested bacteria (63.20–88.10%) and fungi (82.20–86.10%), and also scavenged DPPH (37.48–79.42%) and hydrogen peroxide (20.50–96.50%). In addition, the AgNPs degraded malachite green (78.97%) and methylene blue (25.30%). Furthermore, the AgNPs displayed excellent anticoagulant and thrombolytic activities using human blood. This study has demonstrated the potential of xylanases to synthesise AgNPs which is to the best of our knowledge the first record of such. The present study underscores the relevance of xylanases in nanobiotechnology.Inspec keywords: visible spectra, catalysis, ultraviolet spectra, silver, microorganisms, antibacterial activity, transmission electron microscopy, surface plasmon resonance, nanoparticles, nanofabrication, colloids, blood, Fourier transform infrared spectra, particle sizeOther keywords: Ag, fungal xylanases‐mediated synthesis, silver nanoparticles, catalytic applications, biomedical applications, green synthesis, metallic nanoparticles, Trichoderma longibrachiatum L2, transmission electron microscopy, antimicrobial agents, antioxidant agents, catalytic agents, thrombolytic agents, surface plasmon resonance, spherical nanoparticles, FTIR spectra, anticoagulant agents, colloidal nanoparticles, biomaterials, Aspergillus niger L3, UV‐vis spectroscopy, Fourier transform infrared spectroscopy, protein molecules, DPPH, hydrogen peroxide, malachite green, methylene blue, human blood, nanobiotechnology     

Effects of poly (lactic-co-glycolic acid) as a co-emulsifier on the preparation and hypoglycaemic activity of insulin-loaded solid lipid nanoparticles

Poly (lactic-co-glycolic acid) (PLGA) was used as a co-emulsifier in the preparation of insulin-loaded solid lipid nanoparticles (SLN) with hydrogenated castor oil as lipid matrix and lecithin as surfactant by doubleemulsion technique. The effects of PLGA on the preparation and hypoglycaemic activity of insulin-loaded SLN were studied. The results showed that with the supplement of PLGA, the encapsulation efficiency and loading capacity were increased significantly from 79.08±1.62 to 85.57±3.21% and 1.58±0.03 to 1.71±0.06%, whereas the surface charge and particle size were changed insignificantly from -25.87±2.65 to -22.67±1.19 mv and 431.0±16.1 to 397.0±68.0 nm, respectively. In vivo studies demonstrated that PLGA increased the sustained hypoglycaemic activity from 12 to 36 h and 24 to 120 h in normal and steptozotocin-induced diabetic mice after a single intramuscular injection of the insulin-loaded SLN. These results demonstrated that PLGA could enhance the entrapment of insulin in the nanoparticles, and more importantly, prolong the time of hypoglycaemic activity of the insulin-loaded SLN.     

熔融缩聚法直接合成聚L-乳酸的研究

以L-乳酸为原料,熔融缩聚法直接合成聚L-乳酸.考察了预聚工艺、催化剂配比及用量、反应温度、反应时间及真空度等条件对乳酸聚合反应的影响.通过红外光谱(FTIR)和核磁共振波谱(1H-NMR)分析和表征聚乳酸的结构,凝胶渗透色谱(GPC)测试其分子量及分子量分布.研究表明,较为适宜的工艺条件为:以二水合氯化亚锡(SnCl2·2H2O)和对甲基苯磺酸(TSA)为催化剂,且SrCl2·2H2O相对于乳酸预聚体的质量比为0.5%,真空度-0.98MPa,温度180℃,反应时间10h.得到的聚L-乳酸的粘均分子量为6.17×104,分子量分布1.37,且产率较高,色泽较浅.     

In situ synthesis and magnetic studies of iron oxide nanoparticles in calcium-alginate matrix for biomedical applications

In this work we applied a new route to synthesize magnetic iron oxide nanoparticles into alginate polymer for future application as drug delivery system activated by magnetic external stimuli. Calcium-alginate was used to encapsulate iron oxide nanoparticles, and as scaffold for particle nucleation and its influence on particles size and magnetic properties were studied. The iron oxide mean sizes were between 4.3 and 9.5 nm. Iron is dispersed throughout the polymer matrix mainly as iron oxide particles, and a small fraction as iron (III) occupying calcium sites in the polymer network. The temperature dependence of the Mössbauer spectra is typical of superparamagnetic particles in agreement with the magnetic susceptibility data.