Effect of vapor-phase glutaraldehyde crosslinking on electrospun starch fibers

In this work, we have proven that starch nanofibrous membranes with high tensile strength, water stability and non-cytotoxicity can be produced by electrospinning of starch solution and post-treatment with GTA in vapor phase. GTA vapor phase crosslinking plays a key role in forming water-stable nanofiber membrane and improving the mechanical properties. Comparing with non-crosslinked starch fibers, the crosslinked fibers are increased by nearly 10 times in tensile strength. The crosslinked starch fibrous membranes are non-cytotoxic. They may find applications in the fields of tissue engineering, pharmaceutical therapy and medical.

Biological response of myoblasts to three-dimensional electrically conductive fibrous scaffolds

 Inter-bonded three-dimensional fibrous scaffolds were fabricated using a template-aided melt bonding method. A high-throughput bioreactor was developed for dynamic cell culture of Myoblasts. The scaffolds after surface modification with a conducting polymer, polypyrrole, showed greatly enhanced cell viability, proliferation and differentiation especially under an electrical stimulation.

Characterisation of minimalist co-assembled fluorenylmethyloxycarbonyl self-assembling peptide systems for presentation of multiple bioactive peptides

The nanofibrillar structures that underpin self-assembling peptide (SAP) hydrogels offer great potential for the development of finely tuned cellular microenvironments suitable for tissue engineering. However, biofunctionalisation without disruption of the assembly remains a key issue. SAPS present the peptide sequence within their structure, and studies to date have typically focused on including a single biological motif, resulting in chemically and biologically homogenous scaffolds. This limits the utility of these systems, as they cannot effectively mimic the complexity of the multicomponent extracellular matrix (ECM). In this work, we demonstrate the first successful co-assembly of two biologically active SAPs to form a coassembled scaffold of distinct two-component nanofibrils, and demonstrate that this approach is more bioactive than either of the individual systems alone. Here, we use two bioinspired SAPs from two key ECM proteins: Fmoc-FRGDF containing the RGD sequence from fibronectin and Fmoc-DIKVAV containing the IKVAV sequence from laminin. Our results demonstrate that these SAPs are able to co-assemble to form stable hybrid nanofibres containing dual epitopes. Comparison of the co-assembled SAP system to the individual SAP hydrogels and to a mixed system (composed of the two hydrogels mixed together post-assembly) demonstrates its superior stable, transparent, shear-thinning hydrogels at biological pH, ideal characteristics for tissue engineering applications. Importantly, we show that only the coassembled hydrogel is able to induce in vitro multinucleate myotube formation with C2C12 cells. This work illustrates the importance of tissue engineering scaffold functionalisation and the need to develop increasingly advanced multicomponent systems for effective ECM mimicry.

STATEMENT OF SIGNIFICANCE: Successful control of stem cell fate in tissue engineering applications requires the use of sophisticated scaffolds that deliver biological signals to guide growth and differentiation. The complexity of such processes necessitates the presentation of multiple signals in order to effectively mimic the native extracellular matrix (ECM). Here, we establish the use of two biofunctional, minimalist self-assembling peptides (SAPs) to construct the first co-assembled SAP scaffold. Our work characterises this construct, demonstrating that the physical, chemical, and biological properties of the peptides are maintained during the co-assembly process. Importantly, the coassembled system demonstrates superior biological performance relative to the individual SAPs, highlighting the importance of complex ECM mimicry. This work has important implications for future tissue engineering studies.

Multifunctional Nanoparticles in Cancer: in vitro Characterization, in vivo Distribution

A novel biocompatible and biodegradable polymer, termed poly(Glycerol malate co-dodecanedioate) (PGMD), was prepared by thermal condensation method and used for fabrication of nanoparticles (NPs). PGMD NPs were prepared using the single oil emulsion technique and loaded with an imaging/hyperthermia agent (IR820) and a chemotherapeutic agent (doxorubicin, DOX). The size of the void PGMD NPs, IR820-PGMD NPs and DOX-IR820-PGMD NPs were approximately 90 nm, 110 nm, and 125 nm respectively. An acidic environment (pH=5.0) induced higher DOX and IR820 release compared to pH=7.4. DOX release was also enhanced by exposure to laser, which increased the temperature to 42°C. Cytotoxicity of DOX-IR820-PGMD NPs was comparable in MES-SA but was higher in Dx5 cells compared to free DOX plus IR820 (pIn vivomouse studies showed that NP formulation significantly improved the plasma half-life of IR820 after tail vein injection. Significant lower IR820 content was observed in kidney in DOX-IR820-PGMD NP treatment as compared to free IR820 treatment in our biodistribution studies (p

Evaluación de desenlace: trasplante meniscal versus segunda meniscectomía

Introducción: El incremento de pacientes sintomáticos de rodilla y la osteoartrosis en jóvenes con limitadas posibilidades terapéuticas después de una meniscectomía, genera la búsqueda de alternativas terapéuticas. A pesar que es poco utilizado en Colombia, el trasplante meniscal es una propuesta para el manejo sintomático. Según cifras norteamericanas, se practican entre 700.000 a 1.500.000 artroscopias de rodilla anualmente, el 50% termina en meniscectomía y de este un 40% persisten sintomáticos. Métodos: Estudio de cohorte retrospectivo, con el objetivo de evaluar dolor (Escala Visual Análoga-EVA) y funcionalidad (Escala de Tegner y Lysholm) en los pacientes a quienes se les realizó trasplante meniscal o meniscectomía por segunda vez, entre los años 2007 a 2015. Resultados: A partir de los 6 meses la EVA mostró una tendencia a la mejoría en el grupo de trasplante meniscal, pasando de Moderado a Leve (p: <0.000). La Escala de Tegner y Lysholm cambió de Pobre a Bueno en el grupo de segunda meniscectomía (p= 0.008) y de Bueno a Excelente en el grupo trasplantado (p=0.225). La calificación promedio de la EVA en el grupo de trasplante presentó mejoría (p=<0.000), a diferencia del grupo de segunda meniscectomía (p=0.591). La escala de Tegner y Lysholm, mostró significancia estadística con tendencia a la mejoría en el grupo de segunda meniscectomía. Discusión: Los resultados muestran que con trasplante meniscal hay mejoría del dolor y la funcionalidad versus un segunda meniscectomía. Para fortalecer la evidencia de este tratamiento son necesarios estudios prospectivos complementarios.