A delineating procedure to retrieve relevant publication data in research areas: the case of nanocellulose

Advances concerning publication-level classification system have been demonstrated striking results by dealing properly with emergent, complex and interdisciplinary research areas, such as nanotechnology and nanocellulose. However, less attention has been paid to propose a delineating method to retrieve relevant research areas on specific subjects. This study aims at proposing a procedure to delineate research areas addressed in case nanocellulose. We investigate how a bibliometric analysis could provide interesting insights into research about this sustainable nanomaterial. The research topics clustered by a Publication-level Classification System were used. The procedure involves an iterative process, which includes developing and cleaning a set of core publication regarding the subject and an analysis of clusters they are associated with. Nanocellulose was selected as the subject of study, but the methodology may be applied to any other research area or topic. A discussion about each step of the procedure is provided. The proposed delineation procedure enables us to retrieve relevant publications from research areas involving nanocellulose. Seventeen research topics were mapped and associated with current research challenges on nanocellulose.Merit, Expertise and Measuremen

Hyaluronic acid hydrogels incorporating platelet lysate enhance human pulp cell proliferation and differentiation

The restoration of dentine-pulp complex remains a challenge for dentists; nonetheless, it has been poorly addressed. An ideal system should modulate the host response, as well as enable the recruitment, proliferation and differentiation of relevant progenitor cells. Herein was proposed a photocrosslinkable hydrogel system based on hyaluronic acid (HA) and platelet lysate (PL). PL is a cocktail of growth factors (GFs) and cytokines involved in wound healing orchestration, obtained by the cryogenic processing of platelet concentrates, and was expected to provide the HA hydrogels specific biochemical cues to enhance pulp cellsâ recruitment, proliferation and differentiation. Stable HA hydrogels incorporating PL (HAPL) were prepared after photocrosslinking of methacrylated HA (Met-HA) previously dissolved in PL, triggered by the Ultra Violet activated photoinitiator Irgacure 2959. Both the HAPL and plain HA hydrogels were shown to be able to recruit cells from a cell monolayer of human dental pulp stem cells (hDPSCs) isolated from permanent teeth. The hDPCs were also seeded directly over the hydrogels (5 Ã 104 cells/hydrogel) and cultured in osteogenic conditions. Cell metabolism and DNA quantification were higher, in all time-points, for PL supplemented hydrogels (p < 0,05). Alkaline phosphatase (ALPL) activity and calcium quantification peaks were observed for the HAPL group at 21 days (p < 0,05). The gene expression for ALPL and COLIA1 was up-regulated at 21 days to HAPL, compared with HA group (p < 0,05). Within the same time point, the gene expression for RUNX2 did not differ between the groups. Overall, data demonstrated that the HA hydrogels incorporating PL increased the cellular metabolism and stimulate the mineralized matrix deposition by hDPSCs, providing clear evidence of the potential of the proposed system for the repair of damaged pulp/dentin tissue and endodontics regeneration.LFDA acknowledges Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) for the grant 2014/12017-8. Portuguese Foundation for Science and Technology (FCT) for PSB PhD grant SFRH/BD/73403/2010, MTR post-doctoral grant (SFRH/BPD/111729/2015), MEG grant (IF/00685/2012), and RECOGNIZE project (UTAP-ICDT/CTM-BIO/0023/2014), RL3-TECT - NORTE-07-0124-FEDER-000020 project co-financed by ON.2 (NSRF) through ERD. This study also received financial support from FCT/Ministério da Ciência, Tecnologia, e Ensino Superior (FCT/MCTES) and Fundo Social Europeu through Programa Operacional do Capital Humano (FSE/POCH) PD/59/2013 for the LA ICVS-3Bs (UID/Multi/50026/2013). The authors would like to thank Maurizio Gulino, for its support in the in vitro experiments and Maló Clinic, Porto, Dra Ana Ferro and Dr Bruno Queridinha for the donation of permanent teethinfo:eu-repo/semantics/publishedVersio

Tendon Fascicle-Inspired Nanofibrous Scaffold of Polylactic acid/Collagen with Enhanced 3D-Structure and Biomechanical Properties

Surgical treatment of tendon lesions still yields unsatisfactory clinical outcomes. The use of bioresorbable scaffolds represents a way forward to improve tissue repair. Scaffolds for tendon reconstruction should have a structure mimicking that of the natural tendon, while providing adequate mechanical strength and stiffness. In this paper, electrospun nanofibers of two crosslinked PLLA/Collagen blends (PLLA/Coll-75/25, PLLA/Coll-50/50) were developed and then wrapped in bundles, where the nanofibers are predominantly aligned along the bundles. Bundle morphology was assessed via SEM and high-resolution x-ray computed tomography (XCT). The 0.4-micron resolution in XCT demonstrated a biomimetic morphology of the bundles for all compositions, with a predominant nanofiber alignment and some scatter (50-60% were within 12° from the axis of the bundle), similar to the tendon microstructure. Human fibroblasts seeded on the bundles had increased metabolic activity from day 7 to day 21 of culture. The stiffness, strength and toughness of the bundles are comparable to tendon fascicles, both in the as-spun condition and after crosslinking, with moderate loss of mechanical properties after ageing in PBS (7 and 14 days). PLLA/Coll-75/25 has more desirable mechanical properties such as stiffness and ductility, compared to the PLLA/Coll-50/50. This study confirms the potential to bioengineer tendon fascicles with enhanced 3D structure and biomechanical properties

Catalytic activity of tetravalent metal phosphates and phosphonates on the oxidation of (+)-3-carene

Tetravalent metal phosphates and phosphonates form highly insoluble inorganic polymers and can act as good catalysts in some oxidative reactions. In the present work, zirconium phosphate amorphous (ZrPA), scandium exchanged zirconium phosphate amorphous (ScZrPA), sodium exchanged zirconium phosphate amorphous (NaZrPA), potassium exchanged zirconium phosphate amorphous (KZrPA), zirconium phenylphosphonate amorphous (ZrPPA) and zirconium phenylphosphonate phosphate amorphous (ZrPA/ZrPPA), were prepared and evaluated as catalysts for the oxidation of 3,7,7-trimethylbicyclo[4.1.0]hept-3-ene [(+)-3-carene)] by hydrogen peroxide, in different solvents. It was found that the oxidation reaction of (+)-3-carene yielded three major products, namely alpha-3,4-epoxycarane, carane-3 beta,4 alpha-diol and 3 beta-acetoxycaran-4 alpha-ol, depending on the catalyst and solvent conditions. No beta-3,4-epoxycarane was detected in the studied conditions. (C) 2008 Elsevier B.V. All rights reserved

Injectable hyaluronic acid hydrogels enriched with platelet lysate as a cryostable off-the-shelf system for cell-based therapies

Cell-based regenerative medicine strategies hold a great potential to revolutionize the treatment of a large number of injuries with limited regenerative potential. However, the effectiveness of the simple injection of a cell suspension in a target site/tissue of action is often limited by the dispersion of cells toward other tissues, hindering their therapeutic action. Nevertheless, the development of a custom-made cell carrier that can perfectly fit a patientâ s defect and be ready on demand is still a challenging task. The present study proposes the development of an off-the-shelf injectable cell delivery system combining a photocross-linkable hyaluronic acid (HA) matrix enriched with platelet lysate (PL) and human adipose tissue- derived stem cells (hASCs), which can be stored using standard cryopreservation methods and used when required. The obtained results indicate that the mechanical and viscoelastic properties of the system are improved in the presence of cells and no significant differences were identified between cell- laden hydrogels produced before or after cryopreservation. In PL-enriched hydrogels, cells tend to better recover from cryopreservation maintaining the values of cell viability and DNA content. Moreover, viable cells laden in our system and expressing stemness markers were detected after 21 days in culture. Altogether, the results obtained in this work demon- strate the potential of the developed strategy as an injectable cell delivery system for ready-to-use applications or as a cryo- preserved product to be available on demand for cell-based therapies. The authors wish to acknowledge the financial support from the Portuguese Foundation for Science and Technology (FCT) for the PhD grant of R.C-A (SFRH/BD/96593/2013), post-doctoral grant of M.T.R (SFRH/BPD/111729/2015), grant of M.E.G. (IF/00685/2012) and Recognize project (UTAP-ICDT/CTM-BIO/0023/2014), RL3-TECT - NORTE-07-0124-FEDER-000020 project co-financed by ON.2 (NSRF) through ERD. The authors also acknowledge the financial support from FCT/MCTES (Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia, e Ensino Superior) and the Fundo Social Europeu through Programa Operacional do Capital Humano (FSE/POCH) PD/59/2013 for the PhD grant of A.I.G (PD/BD/113802/2015), and LA ICVS-3Bs (UID/Multi/50026/2013). The authors would also thank to Serviço de Imuno-Hemoterapia, Centro Hospitalar São João, EPE (Porto, Portugal) for providing human platelet concentrate samples.info:eu-repo/semantics/publishedVersio