Jose Luis Lopez-Lacomba

Complutense University of Madrid | UCM

The waste material from the beverage manufacturing industry was valorized as a renewable source for the manufacture of biomaterials capable of acting as scaffolds for tissue engineering. Environmentally friendly design...

Physical hydrogels have been designed for a double purpose: as growth factor delivery systems and as scaffolds to support cell colonization and formation of new bone. Specifically, the polysaccharide gellan gum and the ubiquitous endogenous molecules chondroitin, albumin and spermidine have been used as exclusive components of these hydrogels. The...

The incorporation of cyclodextrins (CDs) to nonviral cationic polymer vectors is very attractive due to recent studies that report a clear improvement of their cytocompatibility and transfection efficiency. However, a systematic study on the influence of the CD derivatization is still lacking. In this work, the relevance of β-CD permethylation has...

Alumina-titanium materials (cermets) of enhanced mechanical properties have been lately developed. In this work, physical properties such as electrical conductivity and the crystalline phases in the bulk material are evaluated. As these new cermets manufactured by spark plasma sintering may have potential application for hard tissue replacements, t...

Statistical copolymers of N-(2-hydroxypropyl) methacrylamide (HPMA) and the dendronic methacrylic monomer 2-(3-(Bis(2-(diethylamino)ethyl)amino)propanamido)ethyl methacrylate (TEDETAMA, derived from N,N,N',N'-tetraethyldiethylenetriamine, TEDETA), were synthesized through radical copolymerization and evaluated in vitro as non-viral gene carriers. T...

A new synthetic strategy for the preparation of methacrylic monomers and polymers carrying acyl β-amino groups is presented. The approach is based on the Michael addition of aliphatic amines onto asymmetric acrylic/methacrylic compounds, reacting the amine highly selectively with the acrylic unit while leaving the methacrylic moiety unreacted. The...

Pseudo-double network hydrogels based on vinylpyrrolidone and anionic methacrylic units were prepared, for the first-time, via a simple one step radical polymerization procedure using thermal or photoinitiation. These networks showed improved mechanical properties, in the hydrated state, compared with their single network cousins and were capable o...

Renewable raw biocompatible materials can be prepared from beer production waste, that due to their nature contain the main chemical components present in bone (phosphorous, silicon, magnesium and calcium). Their characteristics can be tailored for use as replacement candidates in osteoporotic treatments, coatings for prostheses, bone grafts and od...

Numerous strategies that are currently used to regenerate bone depend on employing biocompatible materials exhibiting a scaffold structure. These scaffolds can be manufactured containing particular active compounds, such as hydroxyapatite precursors and/or different growth factors to enhance bone regeneration process. Herein, we have immobilized ca...

Clinical interest on human mesenchymal progenitor cells (hMPC) relies on their potential applicability in cell-based therapies. An in vitro characterization is usually performed in order to define MPC potency. However, in vitro predictions not always correlate with in vivo results and thus there is no consensus in how to really assess cell potency....

Porous ceramic scaffolds are widely studied in the tissue engineering field due to their potential in medical applications as bone substitutes or as bone-filling materials. Solid free form (SFF) fabrication methods allow fabrication of ceramic scaffolds with fully controlled pore architecture, which opens new perspectives in bone tissue regeneratio...

3D MRI study. Video shows the 3D reconstruction of an entire scaffold. Brightness corresponds to seeded cells which colonize all structure. (MOV)

Porous scaffolds are widely tested materials used for various purposes in tissue engineering. A critical feature of a porous scaffold is its ability to allow cell migration and growth on its inner surface. Up to now, there has not been a method to locate live cells deep inside a material, or in an entire structure, using real-time imaging and a non...

A variety of biomaterials have been introduced as potential substrates for cartilage repair. One such candidate is chitosan, which shares some characteristics with glycosaminoglycan and hyaluronic acid present in articular cartilage. Depending on chitosan source and preparation procedure, variations into its properties can be attained. Thus, the ai...

The aim of this work is to investigate the use of bone morphogenetic proteins (rhBMP-2, rhBMP-4) alone or in combination with cells delivered in a calcium alginate gel for the treatment of osteochondral defects. For this purpose, alginate gels were prepared mixing a 2% sodium alginate solution and a 200 mM calcium chloride solution (1:1). Osteochon...

This study focusses on the gene expression profile related to a new rhBMP-2 carrier material, chitosan film. This film could be suitable for use as an osteoinductive coating of commercially available titanium implants. The developed material was characterized, biocompatibility was tested and the cellular response was extensively characterized by tr...

Urea assisted hydroxyapatite (HAp) mineralization was performed on scaffolds composed of a major fraction of multiwall carbon nanotubes (MWCNT, 85 wt.%) and a minor one of chitosan (CHI, 15 wt.%). The MWCNT/CHI scaffolds were synthesized through a cryogenic process (so called ISISA, ice segregation induced self-assembly) that allowed the achievemen...

Ceramic materials are osteoconductive matrices extensively used in bone tissue engineering approaches. The performance of these types of biomaterials can be greatly enhanced by the incorporation of bioactive agents and materials. It is previously reported that chitosan is a biocompatible, biodegradable material that enhances bone formation. In the...

Tissue engineering approaches need biomaterials with suitable properties to provide an appropriate environment for cell attachment and growth. The performance of these biomaterials can be greatly enhanced through the incorporation of bioactive agents. For this reason, we developed chitosan films with cell-attachment ability, rhBMP-2 carrier capacit...

The use of scaffolds composed of a major fraction of multiwall carbon nanotubes (MWCNT, up to 89 wt.%) and a minor one of chitosan (CHI), and with a well-defined microchannel porous structure as biocompatible and biodegradable supports for culture growth is described. Cell adhesion, viability and proliferation onto the external surface of MWCNT/CHI...

N-Methylene phosphonic chitosan (NMPC) was modified with poly(ethyleneglycol)-aldehyde (PEG-CHO) with different molecular weight (200, 2000 and 8000) by reductive amination. The degree of substitution (DS) was determined by elemental analysis. Its chemical identity was characterized by FT-IR, 1H NMR and 13C NMR spectrometry. The crosslinking with P...

Considering the design and development of biomaterials used in tissue engineering, not only is it important that they are biocompatible but also that they induce the desired cellular response for tissue regeneration. Chitosan, a biocompatible and bioresorbable polymer of N-acetylglucosamine and glucosamine is used in our work combined with recombin...

Porcine pancreatic procarboxypeptidase A and its tryptic peptides, carboxypeptidase A and the activation segment, have been studied by high-sensitivity differential scanning calorimetry (DSC). The thermal denaturation of the zymogen and the active enzyme has been carried out at two pH values, 7.5 and 9.0, at different ionic strengths and at differe...

The cryopreservation of intact articular cartilage is constrained by minimal chondrocyte survival. It was the aim of the present study to gain an insight into the permeation kinetics of cryoprotectants through cartilage. This knowledge is essential for achieving adequate tissue permeation prior to cooling. The diffusion coefficients and penetration...

Pulmonary surfactant protein SP-C has been isolated from porcine lungs and treated with dansyl isothiocyanate in chloroform:methanol 2:1 (v/v) solutions,under conditions optimized to introduce a single dansyl group covalently attached to the N-terminalamine group of the protein without loss of its native thioesther-linked palmitic chains. The resul...

The temperature dependence of the heat capacity function of a recombinant streptokinase (rSK) has been studied by high-sensitivity differential scanning microcalorimetry and circular dichroism as a function of pH in low- and high-ionic strength buffers. At low ionic strength it is found that this protein, between pH 7 and 10, undergoes four reversi...

The thermal denaturation of a recombinant human gamma-interferon has been studied as a function of pH in the range from 2 to 10 and buffer concentration in the range from 5 to 100 mM by differential scanning calorimetry, circular dichroism, fluorescence, 1H NMR, and biological activity measurements. The thermal transitions are irreversible at high...

A detailed description of the digital control for a differential scanning microcalorimeter to be used in the study of biomolecules is given. Three control loops and an adequate control program ensure that the instrument works under adiabatic conditions and the temperature difference between the sample and reference cells is as close as possible to...

Flavodoxins are alpha/beta proteins that mediate electron transfer reactions. The conformational stability of apoflavodoxin from Anaboena PCC 7119 has been studied by calorimetry and urea denaturation as a function of pH and ionic strength. At pH > 12, the protein is unfolded. Between pH 11 and pH 6, the apoprotein is folded properly as judged from...

The thermal unfolding of myosin rod, light meromyosin (LMM), and myosin subfragment 2 (S-2) was studied by differential scanning calorimetry (DSC) over the pH range of 6.5-9.0 in 0.5M KCl and either 0.20 M sodium phosphate or 0.15M sodium pyrophosphate. Two rod samples were examined: one was purified by Sephadex G-200 without prior denaturation (na...

Porcine pancreatic procarboxypeptidase A and its tryptic peptides, carboxypeptidase A and the activation segment, have been studied by high-sensitivity differential scanning calorimetry (DSC). The thermal denaturation of the zymogen and the active enzyme has been carried out at two pH values, 7.5 and 9.0, at different ionic strengths and at differe...

A differential scanning calorimetry study of the thermal denaturation of Bacillus thermoproteolyticus rokko thermolysin was carried out. The calorimetric traces were found to be irreversible and highly scan-rate dependent. The shape of the thermograms, as well as their scan-rate dependence, can be explained by assuming that the thermal denaturation...

Brain myelin proteolipid has been investigated using high-sensitivity differential scanning calorimetry (DSC) under various conditions. Crude proteolipid with a 40% (w/w) content of protein gave rise to a reversible transition, centered at about 60 degrees C. The specific enthalpy of the transition was 50 +/- 5 J X g-1 with a calorimetric to van't...