PSEP - Polimers Sintètics: Estructura i Propietats. Polimers Biodegradables.
http://hdl.handle.net/2117/3631
2024-03-28T17:04:28ZIncorporation of functionalized calcium phosphate nanoparticles in living cells
http://hdl.handle.net/2117/362584
Incorporation of functionalized calcium phosphate nanoparticles in living cells
Rivas Cañas, Manuel; Turon, Pau; Alemán Llansó, Carlos; Puiggalí Bellalta, Jordi; Valle Mendoza, Luis Javier del
Intracellular calcium (Ca2+) is a key signaling element that is involved in a great variety of fundamental biological processes. Thus, Ca2+ deregulation would be involved in the cancer cell progression and damage of mitochondrial membrane and DNA, which lead to apoptosis and necrosis. In this study, we have prepared amorphous calcium phosphate nanoparticles (ACP NPs) for studied their incorporation by endocytosis or electroporation to epithelial, endothelial and fibroblast cells (MCF-7, HUVEC and COS-1 cells, respectively). Our results showed that internalized ACP NPs have cytotoxic effects as a consequence of the increase of the intracellular calcium content. The endocytosis pathways showed a greater cytotoxic effect since calcium ions could easily be released from the nanoparticles and be accumulated in the lysosomes and mitochondria. In addition, the cytotoxic effect could be reversed when calcium ion was chelated with ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA). Modification of ACP NPs by coating with different compounds based on phosphates was also evaluated. The results indicated a reduction of the cytotoxic effect, in the order polyphosphate¿<¿phosphonic acid¿<¿orthophosphate. A differential cytotoxic effect of ACP-NPs was observed in function of the cell type; the cytotoxic effect can be ordered as i.e., HUVEC¿>¿COS-1¿>¿MCF-7. The greater cytotoxic effect caused by the increase of intracellular calcium that is observed in normal cells and the greater resistance of cancer cells suggests new perspectives for cancer research.
2022-02-17T14:16:14ZRivas Cañas, ManuelTuron, PauAlemán Llansó, CarlosPuiggalí Bellalta, JordiValle Mendoza, Luis Javier delIntracellular calcium (Ca2+) is a key signaling element that is involved in a great variety of fundamental biological processes. Thus, Ca2+ deregulation would be involved in the cancer cell progression and damage of mitochondrial membrane and DNA, which lead to apoptosis and necrosis. In this study, we have prepared amorphous calcium phosphate nanoparticles (ACP NPs) for studied their incorporation by endocytosis or electroporation to epithelial, endothelial and fibroblast cells (MCF-7, HUVEC and COS-1 cells, respectively). Our results showed that internalized ACP NPs have cytotoxic effects as a consequence of the increase of the intracellular calcium content. The endocytosis pathways showed a greater cytotoxic effect since calcium ions could easily be released from the nanoparticles and be accumulated in the lysosomes and mitochondria. In addition, the cytotoxic effect could be reversed when calcium ion was chelated with ethylene glycol-bis(2-aminoethylether)-N,N,N',N'-tetraacetic acid (EGTA). Modification of ACP NPs by coating with different compounds based on phosphates was also evaluated. The results indicated a reduction of the cytotoxic effect, in the order polyphosphate¿<¿phosphonic acid¿<¿orthophosphate. A differential cytotoxic effect of ACP-NPs was observed in function of the cell type; the cytotoxic effect can be ordered as i.e., HUVEC¿>¿COS-1¿>¿MCF-7. The greater cytotoxic effect caused by the increase of intracellular calcium that is observed in normal cells and the greater resistance of cancer cells suggests new perspectives for cancer research.Nanotheranostic Interface Based on Antibiotic-Loaded Conducting Polymer Nanoparticles for Real-Time Monitoring of Bacterial Growth Inhibition
http://hdl.handle.net/2117/341219
Nanotheranostic Interface Based on Antibiotic-Loaded Conducting Polymer Nanoparticles for Real-Time Monitoring of Bacterial Growth Inhibition
Enshaei, Hamidreza; Puiggalí Jou, Anna; Valle Mendoza, Luis Javier del; Turon, Pau; Saperas Plana, Núria; Alemán Llansó, Carlos
Conducting polymers have been increasingly used as biologically interfacing electrodes for biomedical applications due to their excellent and fast electrochemical response, reversible doping–dedoping characteristics, high stability, easy processability, and biocompatibility. These advantageous properties can be used for the rapid detection and eradication of infections associated to bacterial growth since these are a tremendous burden for individual patients as well as the global healthcare system. Herein, a smart nanotheranostic electroresponsive platform, which consists of chloramphenicol (CAM)-loaded in poly(3,4-ethylendioxythiophene) nanoparticles (PEDOT/CAM NPs) for concurrent release of the antibiotic and real-time monitoring of bacterial growth is presented. PEDOT/CAM NPs, with an antibiotic loading content of 11.9 ± 1.3% w/w, are proved to inhibit the growth of Escherichia coli and Streptococcus sanguinis due to the antibiotic release by cyclic voltammetry. Furthermore, in situ monitoring of bacterial activity is achieved through the electrochemical detection of ß-nicotinamide adenine dinucleotide, a redox active specie produced by the microbial metabolism that diffuse to the extracellular medium. According to these results, the proposed nanotheranostic platform has great potential for real-time monitoring of the response of bacteria to the released antibiotic, contributing to the evolution of the personalized medicine.
2021-03-09T09:10:05ZEnshaei, HamidrezaPuiggalí Jou, AnnaValle Mendoza, Luis Javier delTuron, PauSaperas Plana, NúriaAlemán Llansó, CarlosConducting polymers have been increasingly used as biologically interfacing electrodes for biomedical applications due to their excellent and fast electrochemical response, reversible doping–dedoping characteristics, high stability, easy processability, and biocompatibility. These advantageous properties can be used for the rapid detection and eradication of infections associated to bacterial growth since these are a tremendous burden for individual patients as well as the global healthcare system. Herein, a smart nanotheranostic electroresponsive platform, which consists of chloramphenicol (CAM)-loaded in poly(3,4-ethylendioxythiophene) nanoparticles (PEDOT/CAM NPs) for concurrent release of the antibiotic and real-time monitoring of bacterial growth is presented. PEDOT/CAM NPs, with an antibiotic loading content of 11.9 ± 1.3% w/w, are proved to inhibit the growth of Escherichia coli and Streptococcus sanguinis due to the antibiotic release by cyclic voltammetry. Furthermore, in situ monitoring of bacterial activity is achieved through the electrochemical detection of ß-nicotinamide adenine dinucleotide, a redox active specie produced by the microbial metabolism that diffuse to the extracellular medium. According to these results, the proposed nanotheranostic platform has great potential for real-time monitoring of the response of bacteria to the released antibiotic, contributing to the evolution of the personalized medicine.Variations in cervico-vaginal microbiota among HPV-positive and HPV-negative asymptomatic women in Peru
http://hdl.handle.net/2117/341039
Variations in cervico-vaginal microbiota among HPV-positive and HPV-negative asymptomatic women in Peru
Carrillo Ng, Hugo; Becerra Goicochea, Lorena; Tarazona Castro, Yordi Qesler; Pinillos Vilca, Luis; Valle Mendoza, Luis Javier del; Aguilar Luis, Miguel Angel; Tinco Valdez, Carmen; Silva Caso, Wilmer; Martins Luna, Johanna Elizabeth; Peña Tuesta, Isaac; Aquino Ortega, Ronald; Valle Mendoza, Juana del
Objective:To characterize the cervicovaginal microbiota of HPV-positive and HPV-negative asymptomatic Peruvian women, by identifying the presence of 13 representative bacteria genus.Results:A total of 100 HPV-positive and 100 HPV-negative women were matched by age for comparison of micro-biota. The following bacteria were more frequently identified in HPV-positive patients compared to HPV-negative: Eubacterium (68 vs 32%), Actinobacteria (46 vs 33%), Fusobacterium (11 vs 6%) and Bacteroides (20 vs 13%). A comparison between high-risk and low-risk genotypes was performed and differences were found in the detection of Actinobacteria (50 vs 33.33%), Bifidobacterium (50 vs 20.83%) and Enterococcus (50 vs 29.17%).
2021-03-05T12:37:03ZCarrillo Ng, HugoBecerra Goicochea, LorenaTarazona Castro, Yordi QeslerPinillos Vilca, LuisValle Mendoza, Luis Javier delAguilar Luis, Miguel AngelTinco Valdez, CarmenSilva Caso, WilmerMartins Luna, Johanna ElizabethPeña Tuesta, IsaacAquino Ortega, RonaldValle Mendoza, Juana delObjective:To characterize the cervicovaginal microbiota of HPV-positive and HPV-negative asymptomatic Peruvian women, by identifying the presence of 13 representative bacteria genus.Results:A total of 100 HPV-positive and 100 HPV-negative women were matched by age for comparison of micro-biota. The following bacteria were more frequently identified in HPV-positive patients compared to HPV-negative: Eubacterium (68 vs 32%), Actinobacteria (46 vs 33%), Fusobacterium (11 vs 6%) and Bacteroides (20 vs 13%). A comparison between high-risk and low-risk genotypes was performed and differences were found in the detection of Actinobacteria (50 vs 33.33%), Bifidobacterium (50 vs 20.83%) and Enterococcus (50 vs 29.17%).Gut microbiota in hospitalized children with acute infective gastroenteritis caused by virus or bacteria in a regional Peruvian hospital
http://hdl.handle.net/2117/340738
Gut microbiota in hospitalized children with acute infective gastroenteritis caused by virus or bacteria in a regional Peruvian hospital
Taco Masías, Andre Alonso; Fernández Aristi, Augusto Rafael; Cornejo Tapia, Ángela; Aguilar Luis, Miguel Angel; Valle Mendoza, Luis Javier del; Silva Caso, Wilmer; Zabaleta Gavidia, Víctor; Weilg Espejo, Pablo; Cornejo Pacheres, Hernán; Bazan Mayra, Jorge; Puyen Guerra, Zully Margoth; Valle Mendoza, Juana del
Acute infective gastroenteritis (AIG) is a leading cause of mortality in children worldwide. In Peru, more than 40% of cases of AIG occurring in children under 5 years old. The disruption of the gut microbiota can increase risk for several health complications especially in patients with gastric infections caused by viruses or bacteria. The main objective of this study was to describe the prevalence of 13 representative bacteria from the gut microbiota (GM) in stools samples from children under 5 years of age with acute infective gastroenteritis. The most commonly isolated bacteria from the GM were Firmicutes (63.2% 74/117) Bacteriodetes (62.4%; 73/117), Lactobacillus (59.8%; 70/117), Prevotella (57.2%; 67/117), Proteobacterium (53.8%; 63/117), regardless of the etiological agent responsible for the AIG. Interestingly, despite the high prevalence of Firmicutes, Bacteroidetes, Lactobacillus and Prevotella across all samples, a visible reduction of these agents was observed especially among patients with a single bacterial infection or even bacteria–bacteria coinfections when compared to viral etiologies. Patients with exclusive or mixed breastfeeding registered the highest amount of gut microbiota bacteria, in contrast to infants who received formula or were not breastfed.
2021-03-02T12:38:08ZTaco Masías, Andre AlonsoFernández Aristi, Augusto RafaelCornejo Tapia, ÁngelaAguilar Luis, Miguel AngelValle Mendoza, Luis Javier delSilva Caso, WilmerZabaleta Gavidia, VíctorWeilg Espejo, PabloCornejo Pacheres, HernánBazan Mayra, JorgePuyen Guerra, Zully MargothValle Mendoza, Juana delAcute infective gastroenteritis (AIG) is a leading cause of mortality in children worldwide. In Peru, more than 40% of cases of AIG occurring in children under 5 years old. The disruption of the gut microbiota can increase risk for several health complications especially in patients with gastric infections caused by viruses or bacteria. The main objective of this study was to describe the prevalence of 13 representative bacteria from the gut microbiota (GM) in stools samples from children under 5 years of age with acute infective gastroenteritis. The most commonly isolated bacteria from the GM were Firmicutes (63.2% 74/117) Bacteriodetes (62.4%; 73/117), Lactobacillus (59.8%; 70/117), Prevotella (57.2%; 67/117), Proteobacterium (53.8%; 63/117), regardless of the etiological agent responsible for the AIG. Interestingly, despite the high prevalence of Firmicutes, Bacteroidetes, Lactobacillus and Prevotella across all samples, a visible reduction of these agents was observed especially among patients with a single bacterial infection or even bacteria–bacteria coinfections when compared to viral etiologies. Patients with exclusive or mixed breastfeeding registered the highest amount of gut microbiota bacteria, in contrast to infants who received formula or were not breastfed.Biohydrogel from unsaturated polyesteramide: Synthesis, properties and utilization as electrolytic medium for electrochemical supercapacitors
http://hdl.handle.net/2117/340496
Biohydrogel from unsaturated polyesteramide: Synthesis, properties and utilization as electrolytic medium for electrochemical supercapacitors
Ruano Torres, Guillem; Díaz Andrade, Angélica María; Tononi García, Jordi; Torras Costa, Juan; Puiggalí Bellalta, Jordi; Alemán Llansó, Carlos
The utilization of hydrogels derived from biopolymers as solid electrolyte (SE) of electrochemical supercapacitors (ESCs) is a topic of increasing interest because of their promising applications in biomedicine (e.g. for energy storage in autonomous implantable devices). In this work an unsaturated polyesteramide that contains phenylalanine, butenediol and fumarate as building blocks has been photo-crosslinked to obtain a hydrogel (UPEA-h). The structure of UPEA-h, which is characterized by a network of open interconnected pores surrounded by regions with compact morphology, favors ion transport, while the biodegradability and biocompatibility conferred by the a-amino acid unit and the ester group are appropriated for its usage in the biomedical field. Voltammetric and galvanostatic assays have been conducted to evaluate the behavior of UPEA-h when used as SE in ESCs with poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes. Hence, PEDOT/UPEA-h devices displayed supercapacitor response of up 179 F/g and capacitance retention higher than 90%. Moreover, the long-term stability, leakage-current, and self-discharging response of PEDOT/UPEA-h ESCs reflect the great potential of UPEA-h as ion-conductive electrolyte. Indeed, the performance of PEDOT/UPEA-h is higher than found in analogous devices constructed using other biohydrogels as SE (e.g. ¿-carrageenan, poly-¿-glutamic acid and cellulose hydrogels).
2021-02-25T10:35:10ZRuano Torres, GuillemDíaz Andrade, Angélica MaríaTononi García, JordiTorras Costa, JuanPuiggalí Bellalta, JordiAlemán Llansó, CarlosThe utilization of hydrogels derived from biopolymers as solid electrolyte (SE) of electrochemical supercapacitors (ESCs) is a topic of increasing interest because of their promising applications in biomedicine (e.g. for energy storage in autonomous implantable devices). In this work an unsaturated polyesteramide that contains phenylalanine, butenediol and fumarate as building blocks has been photo-crosslinked to obtain a hydrogel (UPEA-h). The structure of UPEA-h, which is characterized by a network of open interconnected pores surrounded by regions with compact morphology, favors ion transport, while the biodegradability and biocompatibility conferred by the a-amino acid unit and the ester group are appropriated for its usage in the biomedical field. Voltammetric and galvanostatic assays have been conducted to evaluate the behavior of UPEA-h when used as SE in ESCs with poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes. Hence, PEDOT/UPEA-h devices displayed supercapacitor response of up 179 F/g and capacitance retention higher than 90%. Moreover, the long-term stability, leakage-current, and self-discharging response of PEDOT/UPEA-h ESCs reflect the great potential of UPEA-h as ion-conductive electrolyte. Indeed, the performance of PEDOT/UPEA-h is higher than found in analogous devices constructed using other biohydrogels as SE (e.g. ¿-carrageenan, poly-¿-glutamic acid and cellulose hydrogels).Phase-selective conductivity enhancement and cooperativity length in PLLA/TPU nanocomposite blends with carboxylated carbon nanotubes
http://hdl.handle.net/2117/336841
Phase-selective conductivity enhancement and cooperativity length in PLLA/TPU nanocomposite blends with carboxylated carbon nanotubes
Valenti, Sofia; Yousefzade, Omid; Puiggalí Bellalta, Jordi; Macovez, Roberto
Transmission electron microscopy, temperature-modulated differential scanning calorimetry, and broadband dielectric spectroscopy were employed to characterize ternary nanocomposites consisting of carboxylated carbon nanotubes (CNT) dispersed in a blend of two immiscible polymers, poly(L,lactide) (PLLA) and thermoplastic polyurethane (TPU). The nanocomposite blends were obtained by melt-compounding of PLLA and TPU in the presence of 0.2 wt-% CNT, either in the presence or absence of a Joncryl® ADR chain extender for PLLA, leading to reactive and non-reactive melt mixed samples. In both cases, the binary PLLA/TPU blend is characterized by phase separation into submicron TPU droplets dispersed in the PLLA matrix, and displays two separate glass transition temperatures. The carbon nanotubes are present either inside the TPU phase (samples obtained without chain extender), or at their boundaries (reactive-melt mixed samples). The effect of the sub-micron confinement of the TPU component is to decrease the cooperativity length of the primary segmental relaxation of this polymer, which is accentuated by the presence of the CNT fillers. Depending on the type of sample, five or six distinct relaxations are observed by means of dielectric spectroscopy, which we are able to assign to different dielectric phenomena. Our dielectric data show that the CNT fillers do not contribute directly to the long-range charge transport in the nanocomposite blends, consistent with the nanocomposites morphology, but rather result in a shift of the Maxwell-Wagner-Sillars space-charge frequency associated with charge accumulation at the PLLA/TPU boundary. Such shift testifies to a selective conductivity enhancement of the TPU phase due to the filler.
2021-02-03T17:46:01ZValenti, SofiaYousefzade, OmidPuiggalí Bellalta, JordiMacovez, RobertoTransmission electron microscopy, temperature-modulated differential scanning calorimetry, and broadband dielectric spectroscopy were employed to characterize ternary nanocomposites consisting of carboxylated carbon nanotubes (CNT) dispersed in a blend of two immiscible polymers, poly(L,lactide) (PLLA) and thermoplastic polyurethane (TPU). The nanocomposite blends were obtained by melt-compounding of PLLA and TPU in the presence of 0.2 wt-% CNT, either in the presence or absence of a Joncryl® ADR chain extender for PLLA, leading to reactive and non-reactive melt mixed samples. In both cases, the binary PLLA/TPU blend is characterized by phase separation into submicron TPU droplets dispersed in the PLLA matrix, and displays two separate glass transition temperatures. The carbon nanotubes are present either inside the TPU phase (samples obtained without chain extender), or at their boundaries (reactive-melt mixed samples). The effect of the sub-micron confinement of the TPU component is to decrease the cooperativity length of the primary segmental relaxation of this polymer, which is accentuated by the presence of the CNT fillers. Depending on the type of sample, five or six distinct relaxations are observed by means of dielectric spectroscopy, which we are able to assign to different dielectric phenomena. Our dielectric data show that the CNT fillers do not contribute directly to the long-range charge transport in the nanocomposite blends, consistent with the nanocomposites morphology, but rather result in a shift of the Maxwell-Wagner-Sillars space-charge frequency associated with charge accumulation at the PLLA/TPU boundary. Such shift testifies to a selective conductivity enhancement of the TPU phase due to the filler.Heterochirality restricts the self-assembly of phenylalanine dipeptides capped with highly aromatic groups
http://hdl.handle.net/2117/335756
Heterochirality restricts the self-assembly of phenylalanine dipeptides capped with highly aromatic groups
Gil, Ana M.; Casanovas Salas, Jordi; Jimenez Sanz, Ana Isabel; Puiggalí Bellalta, Jordi; Alemán Llansó, Carlos
The influence of stereochemistry on the self-assembly of phenylalanine (Phe) dipeptides bearing aromatic fluorenyl groups at both the N- and C-termini (Fmoc, OFm) has been investigated. For this purpose, Fmoc–d-Phe–l-Phe–OFm and Fmoc–l-Phe–l-Phe–OFm have been examined considering a wide variety of solvents, which differ in dielectric constant and volatility. Results reveal that replacement of l-Phe by d-Phe has a major impact on the self-assembly propensities, restricting drastically the structural diversity and polymorphism shown by the homochiral dipeptide. Thus, the analogous heterochiral dipeptide shows a great propensity to form micro/nanofibers, independently of the environmental conditions. Theoretical calculations revealed that the stability of antiparallel disposition is much higher (a factor of ca. 15) for Fmoc–d-Phe–l-Phe–OFm than that for Fmoc–l-Phe–l-Phe–OFm, which has been attributed to the hydrophobic core formed in the former. Overall, results suggest that control of the backbone chirality is a potent and versatile strategy to drive and finely tune the self-assembly propensities of highly aromatic peptides.
2021-01-21T14:33:43ZGil, Ana M.Casanovas Salas, JordiJimenez Sanz, Ana IsabelPuiggalí Bellalta, JordiAlemán Llansó, CarlosThe influence of stereochemistry on the self-assembly of phenylalanine (Phe) dipeptides bearing aromatic fluorenyl groups at both the N- and C-termini (Fmoc, OFm) has been investigated. For this purpose, Fmoc–d-Phe–l-Phe–OFm and Fmoc–l-Phe–l-Phe–OFm have been examined considering a wide variety of solvents, which differ in dielectric constant and volatility. Results reveal that replacement of l-Phe by d-Phe has a major impact on the self-assembly propensities, restricting drastically the structural diversity and polymorphism shown by the homochiral dipeptide. Thus, the analogous heterochiral dipeptide shows a great propensity to form micro/nanofibers, independently of the environmental conditions. Theoretical calculations revealed that the stability of antiparallel disposition is much higher (a factor of ca. 15) for Fmoc–d-Phe–l-Phe–OFm than that for Fmoc–l-Phe–l-Phe–OFm, which has been attributed to the hydrophobic core formed in the former. Overall, results suggest that control of the backbone chirality is a potent and versatile strategy to drive and finely tune the self-assembly propensities of highly aromatic peptides.Development of an antimicrobial and antioxidant hydrogel/nano-electrospun wound dressing
http://hdl.handle.net/2117/335399
Development of an antimicrobial and antioxidant hydrogel/nano-electrospun wound dressing
Valle Mendoza, Luis Javier del; Labra Vázquez, Pablo; Puiggalí Bellalta, Jordi; Romero Montero, Alejandra; García Arrazola, Roeb; Montiel, Carmina; Gimeno Seco, Miquel
A nanocomposite based on an antibiotic-loaded hydrogel into a nano-electrospun fibre with antimicrobial and antioxidant capacities is investigated. The material is composed of nanofibres of enzymatic PCL grafted with poly(gallic acid) (PGAL), a recently developed enzyme-mediated hydrophilic polymer that features a multiradical and polyanionic nature in a helicoidal secondary structure. An extensive experimental–theoretical study on the molecular structure and morphological characterizations for this nanocomposite are discussed. The hydrogel network is formed by sodium carboxymethylcellulose (CMC) loaded with the broad-spectrum antibiotic clindamycin. This nano electrospun biomaterial inhibits a strain of Staphylococcus aureus, which is the main cause of nosocomial infections. The SPTT assay demonstrates that PGAL side chains also improve the release rates for this bactericide owing to the crosslinking to the CMC hydrogel matrix. The absence of hemolytic activity and the viability of epithelial cells demonstrates that this nanocomposite has no cytotoxicity.
2021-01-15T11:36:07ZValle Mendoza, Luis Javier delLabra Vázquez, PabloPuiggalí Bellalta, JordiRomero Montero, AlejandraGarcía Arrazola, RoebMontiel, CarminaGimeno Seco, MiquelA nanocomposite based on an antibiotic-loaded hydrogel into a nano-electrospun fibre with antimicrobial and antioxidant capacities is investigated. The material is composed of nanofibres of enzymatic PCL grafted with poly(gallic acid) (PGAL), a recently developed enzyme-mediated hydrophilic polymer that features a multiradical and polyanionic nature in a helicoidal secondary structure. An extensive experimental–theoretical study on the molecular structure and morphological characterizations for this nanocomposite are discussed. The hydrogel network is formed by sodium carboxymethylcellulose (CMC) loaded with the broad-spectrum antibiotic clindamycin. This nano electrospun biomaterial inhibits a strain of Staphylococcus aureus, which is the main cause of nosocomial infections. The SPTT assay demonstrates that PGAL side chains also improve the release rates for this bactericide owing to the crosslinking to the CMC hydrogel matrix. The absence of hemolytic activity and the viability of epithelial cells demonstrates that this nanocomposite has no cytotoxicity.Semi-interpenetrated hydrogels-microfibers electroactive assemblies for release and real-time monitoring of drugs
http://hdl.handle.net/2117/334778
Semi-interpenetrated hydrogels-microfibers electroactive assemblies for release and real-time monitoring of drugs
Moghimiardekani, Ali; Molina García, Brenda Guadalupe; Enshaei, Hamidreza; Valle Mendoza, Luis Javier del; Pérez Madrigal, Maria del Mar; Estrany Coda, Francesc; Alemán Llansó, Carlos
Simultaneous drug release and monitoring using a single polymeric platform represents a significant advance in the utilization of biomaterials for therapeutic use. Tracking drug release by real-time electrochemical detection using the same platform is a simple way to guide the dosage of the drug, improve the desired therapeutic effect, and reduce the adverse side effects. The platform developed in this work takes advantage of the flexibility and loading capacity of hydrogels, the mechanical strength of microfibers, and the capacity of conducting polymers to detect the redox properties of drugs. The engineered platform is prepared by assembling two spin-coated layers of poly-¿-glutamic acid hydrogel, loaded with poly(3,4-ethylenedioxythiophene) (PEDOT) microparticles, and separated by a electrospun layer of poly-e-caprolactone microfibers. Loaded PEDOT microparticles are used as reaction nuclei for the polymerization of poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PHMeDOT), that semi-interpenetrate the whole three layered system while forming a dense network of electrical conduction paths. After demonstrating its properties, the platform is loaded with levofloxacin and its release monitored externally by UV–vis spectroscopy and in situ by using the PHMeDOT network. In situ real-time electrochemical monitoring of the drug release from the engineered platform holds great promise for the development of multi-functional devices for advanced biomedical applications.
2020-12-22T11:35:45ZMoghimiardekani, AliMolina García, Brenda GuadalupeEnshaei, HamidrezaValle Mendoza, Luis Javier delPérez Madrigal, Maria del MarEstrany Coda, FrancescAlemán Llansó, CarlosSimultaneous drug release and monitoring using a single polymeric platform represents a significant advance in the utilization of biomaterials for therapeutic use. Tracking drug release by real-time electrochemical detection using the same platform is a simple way to guide the dosage of the drug, improve the desired therapeutic effect, and reduce the adverse side effects. The platform developed in this work takes advantage of the flexibility and loading capacity of hydrogels, the mechanical strength of microfibers, and the capacity of conducting polymers to detect the redox properties of drugs. The engineered platform is prepared by assembling two spin-coated layers of poly-¿-glutamic acid hydrogel, loaded with poly(3,4-ethylenedioxythiophene) (PEDOT) microparticles, and separated by a electrospun layer of poly-e-caprolactone microfibers. Loaded PEDOT microparticles are used as reaction nuclei for the polymerization of poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PHMeDOT), that semi-interpenetrate the whole three layered system while forming a dense network of electrical conduction paths. After demonstrating its properties, the platform is loaded with levofloxacin and its release monitored externally by UV–vis spectroscopy and in situ by using the PHMeDOT network. In situ real-time electrochemical monitoring of the drug release from the engineered platform holds great promise for the development of multi-functional devices for advanced biomedical applications.Microstructural changes during degradation of biobased poly(4-hydroxybutyrate) sutures
http://hdl.handle.net/2117/334754
Microstructural changes during degradation of biobased poly(4-hydroxybutyrate) sutures
Keridou, Ina; Franco García, María Lourdes; Valle Mendoza, Luis Javier del; Funk, Lutz; Turon, Pau; Puiggalí Bellalta, Jordi
Fibers of poly(4-hydroxybutyrate) (P4HB) have been submitted to both hydrolytic and enzymatic degradation media in order to generate samples with different types and degrees of chain breakage. Random chain hydrolysis is clearly enhanced by varying temperatures from 37 to 55 ¿C and is slightly dependent on the pH of the medium. Enzymatic attack is a surface erosion process with significant solubilization as a consequence of a preferent stepwise degradation. Small angle X-ray diffraction studies revealed a peculiar supramolecular structure with two different types of lamellar stacks. These were caused by the distinct shear stresses that the core and the shell of the fiber suffered during the severe annealing process. External lamellae were characterized by surfaces tilted 45¿ with respect to the stretching direction and a higher thickness, while the inner lamellae were more imperfect and had their surfaces perpendicularly oriented to the fiber axis. In all cases, WAXD data indicated that the chain molecular axis was aligned with the fiber axis and molecules were arranged according to a single orthorhombic structure. A gradual change of the microstructure was observed as a function of the progress of hydrolysis while changes were not evident under an enzymatic attack. Hydrolysis mainly affected the inner lamellar stacks as revealed by the direct SAXS patterns and the analysis of correlation functions. Both lamellar crystalline and amorphous thicknesses slightly increased as well as the electronic contrast between amorphous and crystalline regions. Thermal treatments of samples exposed to the hydrolytic media revealed microstructural changes caused by degradation, with the inner lamellae being those that melted faster
2020-12-22T08:58:30ZKeridou, InaFranco García, María LourdesValle Mendoza, Luis Javier delFunk, LutzTuron, PauPuiggalí Bellalta, JordiFibers of poly(4-hydroxybutyrate) (P4HB) have been submitted to both hydrolytic and enzymatic degradation media in order to generate samples with different types and degrees of chain breakage. Random chain hydrolysis is clearly enhanced by varying temperatures from 37 to 55 ¿C and is slightly dependent on the pH of the medium. Enzymatic attack is a surface erosion process with significant solubilization as a consequence of a preferent stepwise degradation. Small angle X-ray diffraction studies revealed a peculiar supramolecular structure with two different types of lamellar stacks. These were caused by the distinct shear stresses that the core and the shell of the fiber suffered during the severe annealing process. External lamellae were characterized by surfaces tilted 45¿ with respect to the stretching direction and a higher thickness, while the inner lamellae were more imperfect and had their surfaces perpendicularly oriented to the fiber axis. In all cases, WAXD data indicated that the chain molecular axis was aligned with the fiber axis and molecules were arranged according to a single orthorhombic structure. A gradual change of the microstructure was observed as a function of the progress of hydrolysis while changes were not evident under an enzymatic attack. Hydrolysis mainly affected the inner lamellar stacks as revealed by the direct SAXS patterns and the analysis of correlation functions. Both lamellar crystalline and amorphous thicknesses slightly increased as well as the electronic contrast between amorphous and crystalline regions. Thermal treatments of samples exposed to the hydrolytic media revealed microstructural changes caused by degradation, with the inner lamellae being those that melted faster