Antonio Luis Medina Castillo - Academia.edu (original) (raw)

Papers by Antonio Luis Medina Castillo

Objectives: To evaluate the adsorption of bone related proteins and bioactivity ofexperimentalfun... more Objectives: To evaluate the adsorption of bone related proteins and bioactivity ofexperimentalfunctionalized (carboxylated oraminated) polymeric membranes for bone regeneration.Methods: Polymethylmethacrylate-based membranes functionalized with carboxyl or aminoradicalswere tested. Membranes were zinc loaded and the adsorption isotherms of zinc were studied. A commercially available polytetrafluoroethylene membrane was used as control. Human plasma proteins, bovine serum albumin, fibrinogen and fibronectin adsorption were measured with a spectrophotometer applying an acid determination protocol. Biomimetic calcium phosphate precipitation on polymeric membraneswas also assessedtroughsimulated body fluid immersion. Scanning electron microscopy and elemental analysis by means of an energy dispersive system were used for mineral deposits identification.Results: Both experimental membranes produced higher protein adsorption than the commercial control that does not adsorb proteins. Carbo...

International Endodontic Journal, 2020

Reinfection and tooth fracture are the most common causes of failure after endodontical treatment... more Reinfection and tooth fracture are the most common causes of failure after endodontical treatment. Aim: The purposes of this study were to evaluate the antimicrobial and inhibition of biofilm formation potential of novel remineralizing polymeric nanoparticles (NPs) when applied on the dentine surface; and to ascertain the effect of the functionalization of these NPs with zinc, calcium or doxycycline. Methodology: The antimicrobial activity and the inhibition of biofilm formation have been analyzed on human dentine blocks that were infected with Enterococcus faecalis before or after NPs application. LIVE/DEAD  testing under the confocal laser scanning microscopy and bacterial culturing were employed to analyse the biofilm biovolume and the bacterial viability. Field Emission Scanning Electron Microscopy was also employed to assess the biofilm morphology. One-way ANOVA with Welch's correction and post-hoc comparison by the Games-Howell test were performed for comparisons between groups. Results: The un-functionalized NPs displayed the highest antimicrobial activity against E. faecalis biofilms as they provided the lowest biovolume (3,865.7 µm 3) and the highest dead/injured cells percentage (79.93%), followed by Dox-NPs (biovolume: 19,041.55 µm 3 , dead/injured cells: 45.53%). Doxycycline loaded NPs showed the highest values of inhibition of biofilm formation with the lowest biofilm biovolume (8,517.65 µm3) and a high dead/injured bacterial percentage (68.68%). Un-functionalized NPs did not reduce biomass growth, but exerted the highest percentage of compromised cells (93%), being able to disrupt biofilm formation. It also produced occlusion of dentinal tubules, probably interfering with bacterial tubule penetration. Conclusions: A new generation of bioactive nano-fillers (doxycyclinefunctionalized polymeric NPs) which may be included as primers in endodontic sealers, promoting antibacterial activity and dentinal tubules occlusion is proposed.

Dental Materials, 2021

Objective. To investigate the effect of novel polymeric nanoparticles (NPs) doped with melatonin ... more Objective. To investigate the effect of novel polymeric nanoparticles (NPs) doped with melatonin (ML) on nano-hardness, crystallinity and ultrastructure of the formed hydroxyapatite after endodontic treatment. Methods. Undoped-NPs and ML-doped NPs (ML-NPs) were tested at radicular dentin, after 24 h and 6 m. A control group without NPs was included. Radicular cervical and apical dentin surfaces were studied by nano-hardness measurements, X-ray diffraction and transmission electron microscopy. Mean and standard deviation were analyzed by ANOVA and Student-Newman-Keuls multiple comparisons (p < 0.05). Results. Cervical dentin treated with undoped NPs maintained its nano-hardness values after 6 m of storage being [24 h: 0.29 (0.01); 6 m: 0.30 (0.02) GPa], but it decreased at apical dentin [24 h: 0.36 (0.01); 6 m: 0.28 (0.02) GPa]. When ML-NPs were used, nano-hardness was similar over time [24h: 0.31 (0.02); 6 m: 0.28 (0.03) GPa], at apical dentin. Root dentin treated with ML-NPs produced, in general, high crystallinity of new minerals and thicker crystals than those produced in the rest of the groups. After 6 m, crystals became organized in randomly oriented polyhedral, square polygonal block-like apatite or drop-like apatite polycrystalline lattices when ML-NPs were used. Undoped NPs generated poor crystallinity, with preferred orientation of small crystallite and increased microstrain.

Polymers, 2021

Polymeric membranes are employed in guided bone regeneration (GBR) as physical barriers to facili... more Polymeric membranes are employed in guided bone regeneration (GBR) as physical barriers to facilitate bone in-growth. A bioactive and biomimetic membrane with the ability to participate in the healing and regeneration of the bone is necessary. The aim of the present study was to analyze how novel silicon dioxide composite membranes functionalized with zinc or doxycycline can modulate the osteoblasts’ proliferation, differentiation, and expression of selected antigenic markers related to immunomodulation. Nanostructured acrylate-based membranes were developed, blended with silica, and functionalized with zinc or doxycycline. They were subjected to MG63 osteoblast-like cells culturing. Proliferation was assessed by MTT-assay, differentiation by evaluating the alkaline phosphatase activity by a spectrophotometric method and antigenic phenotype was assessed by flow cytometry for selected markers. Mean comparisons were conducted by one-way ANOVA and Tukey tests (p < 0.05). The blendin...

Polymers, 2020

Most of the polymers used as biomaterials for scaffolds are naturally occurring, synthetic biodeg... more Most of the polymers used as biomaterials for scaffolds are naturally occurring, synthetic biodegradable, and synthetic non-biodegradable polymers. Since synthetic polymers can be adapted for obtaining singular desired characteristics by applying various fabrication techniques, their use has increased in the biomedical field, in dentistry in particular. The manufacturing methods of these new structures include many processes, such as electrospinning, 3D printing, or the use of computer-aided design/computer-aided manufacturing (CAD/CAM). Synthetic polymers show several drawbacks that can limit their use in clinical applications, such as the lack of cellular recognition, biodegradability, and biocompatibility. Moreover, concerning biodegradable polymers, the time for matrix resorption is not predictable, and non-resorbable matrices are preferred for soft tissue augmentation in the oral cavity. This review aimed to determine a new biomaterial to offset the present shortcomings in the ...

Journal of Dentistry, 2020

Objectives: To assess the surface characteristics and composition that may enhance osteoblasts vi... more Objectives: To assess the surface characteristics and composition that may enhance osteoblasts viability on novel electrospun composite membranes (organic polymer/silicon dioxide nanoparticles). Methods: Membranes are composed by a novel polymer blend, the mixture of two hydrophilic copolymers 2-hydroxyethylmethacrylate-co-methylmethacrylate and 2hydroxyethylacrylate-co-methylacrylate, and they are doped with silicon dioxide nanoparticles. Then the membranes were functionalized with zinc or doxycycline. The membranes were morphologically characterized by atomic force and scanning electron microscopy (FESEM), and mechanically probed using a nanoindenter. Biomimetic calcium phosphate precipitation on polymeric tissues was assessed. Cell viability tests were performed using human osteosarcoma cells. Cells morphology was also studied by FESEM. Data were analyzed by ANOVA, Student-Newman-Keuls and Student t tests (p<0.05). Results: Silica doping of membranes enhanced bioactivity and increased mechanical properties. Membranes morphology and mechanical properties were similar to those of trabecular bone. Zinc and doxycycline doping did not exert changes but it increased novel membranes bioactivity. Membranes were found to permit osteoblasts proliferation. Silica-doping favored cells proliferation and spreading. As soon as 24h after the seeding, cells in silica-doped membranes were firmly attached to experimental tissues trough filopodia, connected to each other. The cells produced collagen and minerals onto the surfaces. Conclusions: Silica nanoparticles enhanced surface properties and osteoblasts viability on electrospun membranes. Clinical significance: The ability of silica-doped matrices to promote precipitation of calcium phosphate, together with their mechanical properties, observed non-toxicity, stimulating effect on osteoblasts and its surface chemistry allowing covalent binding of proteins, offer a potential strategy for bone regeneration applications.

Journal of the Mechanical Behavior of Biomedical Materials, 2020

The effectiveness of novel polymeric nanoparticles (NPs) application in reducing dentin permeabil... more The effectiveness of novel polymeric nanoparticles (NPs) application in reducing dentin permeability and facilitating dentin remineralization after endodontic treatment was evaluated. The effect of undoped NPs, zinc, calcium and doxycycline-doped NPs (Zn-NPs, Ca-NPs and D-NPs, respectively) was tested in radicular dentin. A control group without NPs was included. Radicular dentin was assessed for fluid filtration. Dentin remineralization was analyzed by scanning and transmission electron microscopy, energy-dispersive analysis, AFM, Young´s modulus (Ei), Nano DMA, Raman, and X-Ray Diffraction analysis. Ca-NPs and Zn-NPs treated dentin exhibited the lowest microleakage with hermetically sealed dentinal tubules and a zinc-based salt generation onto dentin. Zn-NPs favored crystallinity and promoted the highest Ei and functional remineralization at the apical dentin, generating differences between the values of complex modulus among groups. Ca-NPs produced closure of tubules and porosities at the expense of a relative mineral amorphization, without creating zones of stress concentration. The highest sealing efficacy was obtained in Zn-NPs-treated samples, along with the highest values of Young´s modulus and dentin mineralization. These high values of Ei were obtained by closing voids, cracks, pores and tubules, and by strengthening the root dentin. When using undoped NPs or Ca-NPs, deposition of minerals occurred, but radicular dentin was not mechanically reinforced. Therefore, application of Zn-NPs in endodontically treated teeth previous to the canal filling is encouraged.

Materials (Basel, Switzerland), Jan 14, 2018

Polymeric nanoparticles were modified to exert antimicrobial activity against oral bacteria. Nano... more Polymeric nanoparticles were modified to exert antimicrobial activity against oral bacteria. Nanoparticles were loaded with calcium, zinc and doxycycline. Ions and doxycycline release were measured by inductively coupled plasma optical emission spectrometer and high performance liquid chromatography. , , , and were grown and the number of bacteria was determined by optical density. Nanoparticles were suspended in phosphate-buffered saline (PBS) at 10, 1 and 0.1 mg/mL and incubated with 1.0 mL of each bacterial suspension for 3, 12, and 24 h. The bacterial viability was assessed by determining their ability to cleave the tetrazolium salt to a formazan dye. Data were analyzed by ANOVA and Scheffe’s F ( < 0.05). Doxycycline doping efficacy was 70%. A burst liberation effect was produced during the first 7 days. After 21 days, a sustained release above 6 µg/mL, was observed. Calcium and zinc liberation were about 1 and 0.02 µg/mL respectively. The most effective ant...

International endodontic journal, Jan 28, 2018

To investigate if crystallinity and ultrastructure are modified when cervical dentine is treated ... more To investigate if crystallinity and ultrastructure are modified when cervical dentine is treated with four different nanogels-based solutions for remineralizing purposes. Experimental nanogels based on polymeric nanoparticles (NPs) and zinc, calcium or doxycycline-loaded NPs were applied to citric acid etched dentine to facilitate the occlusion of tubules and the mineralization of the dentine surface. Dentine surfaces were studied by X-ray diffraction and transmission electron microscopy through selected area diffraction and bright-field imaging. Crystals at the dentine surface were identified as hydroxyapatite with the highest crystallographic maturity and crystallite size in dentine treated with Zn-NPs-based gel. Texture increased in all samples from 24 h to 7 days, except in dentine surfaces treated with Zn-NPs gel. Polyhedral, plate-like and drop-like shaped apatite crystals constituted the bulk of minerals in dentine treated with Zn-NPs gel, after 7 days. Polymorphic, cubic and...

Clinical Oral Investigations, 2017

Objective: Characterization of novel calcium and zinc loaded electrospun matrices for periodontal... more Objective: Characterization of novel calcium and zinc loaded electrospun matrices for periodontal regeneration. Materials and Methods: A polymethylmetacrylate-based membrane was calcium or zinc loaded. Matrices were characterized morphologically by atomic force and scanning electron microscopy, and mechanically probed by a nanoindenter. Biomimetic calcium phosphate precipitation on polymeric tissues was assessed. Cell viability tests were performed using oral mucosa fibroblasts. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests or by ANOVA and Student-Newman-Keuls multiple comparisons. Results: Zinc and calcium loading on matrices did not modify their morphology but increased nanomechanical properties and decreased nanoroughness. Precipitation of calcium and phosphate on the matrices surfaces was observed in zinc-loaded specimens. Matrices were found to be non-toxic to cells in all the assays. Calcium and zinc-loaded scaffolds presented a very low cytotoxic effect. Conclusions: Zinc-loaded membranes permit cells viability and promoted mineral precipitation in physiological conditions. Based on the tested nanomechanical properties and scaffold architecture, the proposed membranes may be suitable for cell proliferation. Clinical Relevance: The ability of zinc-loaded matrices to promote precipitation of calcium phosphate deposits, together with their observed non-toxicity and its surface chemistry allowing covalent binding of proteins, may offer new strategies for periodontal regeneration.

Clinical Oral Investigations, 2016

Zinc-modified nanopolymers improve the quality of resin-dentin bonded interfaces.

Nanomaterials, 2021

Tubule occlusion and remineralization are considered the two main goals of dentin hypersensitivit... more Tubule occlusion and remineralization are considered the two main goals of dentin hypersensitivity treatment. The objective is to assess the ability of dentifrices containing zinc-doped polymeric nanoparticles (NPs) to enduringly occlude the dentinal tubules, reinforcing dentin’s mechanical properties. Fifteen dentin surfaces were acid-treated for dentinal tubule exposure and brushed with (1) distilled water, or with experimental pastes containing (2) 1% of zinc-doped NPs, (3) 5% of zinc-doped NPs, (4) 10% of zinc-doped NPs or (5) Sensodyne®. Topographical and nanomechanical analyses were performed on treated dentin surfaces and after a citric acid challenge. ANOVA and Student–Newman–Keuls tests were used (p < 0.05). The main results indicate that all pastes produced tubule occlusion (100%) and reinforced mechanical properties of intertubular dentin (complex modulus was above 75 GPa). After the citric acid challenge, only those pastes containing zinc-doped NPs were able to mainta...

Aviso: Se puede realizar consulta prevista por el art. 41 LP 24/2015. Dentro de los seis meses si... more Aviso: Se puede realizar consulta prevista por el art. 41 LP 24/2015. Dentro de los seis meses siguientes a la publicación de la concesión en el Boletín Oficial de la Propiedad Industrial cualquier persona podrá oponerse a la concesión. La oposición deberá dirigirse a la OEPM en escrito motivado y previo pago de la tasa correspondiente (art. 43 LP 24/2015). ES 2 721 675 B2 conductos radiculares no es un desafío nuevo; varios materiales han sido propuestos previamente: Una mezcla triple de antibióticos (TAM) se ha utilizado recientemente como medicación intracanal contra los patógenos comúnmente encontrados en el sistema del canal de la raíz. Esta mezcla contiene ciprofloxacina, metronidazol y minociclina y puede eliminar bacterias de forma efectiva, pero tiene dos importantes desventajas:

polymeric compounds with immobilizing properties. # The present invention relates to polymeric co... more polymeric compounds with immobilizing properties. # The present invention relates to polymeric compounds immobilizing properties of biomolecules. Such materials comprise a core of super-paramagnetic nanoparticles hybrid vinylsulfone groups and to carry out the immobilization of biomolecules. Furthermore, the present invention relates to a method of synthesis of such polymeric compounds.

La presente invention concerne des composes polymeres a proprietes immobilisantes sur des biomole... more La presente invention concerne des composes polymeres a proprietes immobilisantes sur des biomolecules. Lesdits materiaux comprennent un noyau de particules hybrides super-paramagnetiques et des groupes vinylsulfone pour assurer l'immobilisation des biomolecules. La presente invention concerne egalement un procede de synthese desdits composes polymeres.

Acta Biomaterialia, 2020

The objective was to assess doxycycline (Dox) and zinc (Zn) doped nanoparticles' (NPs) potent... more The objective was to assess doxycycline (Dox) and zinc (Zn) doped nanoparticles' (NPs) potential to protect the resin-dentin interface from cariogenic biofilm. Three groups of polymeric NPs were tested: unloaded, loaded with zinc and with doxycycline. NPs were applied after dentin etching. The disks were exposed to a cariogenic biofilm challenge in a Drip-Flow Reactor during 72 h and 7 d. Half of the specimens were not subjected to biofilm formation but stored 72 h and 7 d. LIVE/DEAD® viability assay, nano-dynamic mechanical assessment, Raman spectroscopy and field emission electron microscopy (FESEM) analysis were performed. The measured bacterial death rates, at 7 d were 46% for the control group, 51% for the undoped-NPs, 32% for Dox-NPs, and 87% for Zn-NPs; being total detected bacteria reduced five times in the Dox-NPs group. Zn-NPs treated samples reached, in general, the highest complex modulus values at the resin-dentin interface over time. Regarding the mineral content, Zn-NPs-treated dentin interfaces showed the highest mineralization degree associated to the phosphate peak and the relative mineral concentration. FESEM images after Zn-NPs application permitted to observe remineralization of the etched and non-resin infiltrated collagen layer, and bacteria were scarcely encountered. The combined antibacterial and remineralizing effects, when Zn-NPs were applied, reduced biofilm formation. Dox-NPs exerted an antibacterial role but did not remineralize the bonded interface. Undoped-NPs did not improve the properties of the interfaces. Application of Zn-doped NPs during the bonding procedure is encouraged. Statement of significance Application of Zn-doped nanoparticles on acid etched dentin reduced biofilm formation and viability at the resin-dentin interface due to both remineralization and antibacterial properties. Doxycycline-doped nanoparticles also diminished oral biofilm viability, but did not remineralize the resin-dentin interface.

Journal of Dentistry, 2020

Clinical Oral Investigations, 2018

International Endodontic Journal, 2020

Dental Materials, 2021

Polymers, 2021

Polymers, 2020

Journal of Dentistry, 2020

Journal of the Mechanical Behavior of Biomedical Materials, 2020

Materials (Basel, Switzerland), Jan 14, 2018

International endodontic journal, Jan 28, 2018

Clinical Oral Investigations, 2017

Clinical Oral Investigations, 2016

Zinc-modified nanopolymers improve the quality of resin-dentin bonded interfaces.

Nanomaterials, 2021

Acta Biomaterialia, 2020

Journal of Dentistry, 2020

Clinical Oral Investigations, 2018