Grain boundary corrosion in TiO2 bone scaffolds doped with group II cations

A pH drop during the inflammatory phase during bone regeneration can cause corrosion in TiO2 bone scaffolds and the loss of compressive strength. Corrosion as ion leaching and dissolution is confined to grain boundaries. Cationic doping of TiO2 showed to increase the compressive strength but increased the amount of impurities in grain boundaries as well. Therefore, this study showed the different grain boundary formation for Ca, Sr and Mg doped scaffolds and their corrosion behavior. After corrosion, the amorphous phase in grain boundaries was dissolved in all doped scaffolds. Differences occurred due to the formation of an additional crystalline phase in Sr doped scaffolds. The presence of an amorphous and crystalline phase led to an inhomogeneous dissolution in grain boundaries and a significant decrease in compressive strength already after 4 h in contact with an acidic environment. Released ions did not show any cytotoxic effect on hASCs. Mg doped TiO2 scaffolds led to sig- nificant increased osteogenic differentiation.(undefined)info:eu-repo/semantics/publishedVersio

Xeno-free bioengineered human skeletal muscle tissue using human platelet lysate-based hydrogels

Bioengineered human skeletal muscle tissues have emerged in the last years as new in vitro systems for disease modeling. These bioartificial muscles are classically fabricated by encapsulating human myogenic precursor cells in a hydrogel scaffold that resembles the extracellular matrix. However, most of these hydrogels are derived from xenogenic sources, and the culture media is supplemented with animal serum, which could interfere in drug testing assays. On the contrary, xeno-free biomaterials and culture conditions in tissue engineering offer increased relevance for developing human disease models. In this work, we used human platelet lysate-based nanocomposite hydrogels (HUgel) as scaffolds for human skeletal muscle tissue engineering. These hydrogels consist of human platelet lysate reinforced with cellulose nanocrystals (a-CNC) that allow tunable mechanical, structural, and biochemical properties for the 3D culture of stem cells. Here, we developed hydrogel casting platforms to encapsulate human muscle satellite stem cells in HUgel. The a-CNC content was modulated to enhance matrix remodeling, uniaxial tension, and self-organization of the cells, resulting in the formation of highly aligned, long myotubes expressing sarcomeric proteins. Moreover, the bioengineered human muscles were subjected to electrical stimulation, and the exerted contractile forces were measured in a non-invasive manner. Overall, our results demonstrated that the bioengineered human skeletal muscles could be built in xeno-free cell culture platforms to assess tissue functionality, which is promising for drug development applications

Natural materials

The use of naturally occurring materials as scaffolds to support cell growth and proliferation significantly impacted the origin and progress of tissue engineering and regenerative medicine. However, the majority of these materials failed to provide adequate cues to guide cell differentiation toward the formation of new tissues. Over the past decade, a new generation of multifunctional and smart natural-based materials has been developed to provide biophysical and biochemical cues intended to specifically guide cell behavior. In this chapter, the use of extracellular matrix proteins and blood-derivatives intrinsic capacity to mimic the biophysical and biological characteristics of native tissues is reviewed. Furthermore, the design of a variety of nanostructures using the well-explored characteristics of nucleic acids is summarized. In the second section, the exploitation of supramolecular chemistry to create new dynamic functional hydrogels that mimic the extracellular matrix structure and/or composition is surveyed. Then, the incorporation of nanoelements in polymeric networks for the design of smart nanocomposite materials with tailored functionalities to guide cell behavior is introduced. Finally, the future perspectives in the development of new biomaterials for tissue engineering and regenerative medicine are presented.Te authors acknowledge the fnancial support of the European Union Framework Programme for Research and Innovation Horizon 2020, under the TEAMING grant agreement No 739572 – Te Discoveries CTR, Marie Skłodowska-Curie grant agreement No 706996 and European Research Council grant agreement No 726178; FCT (Fundação para a Ciência e a Tecnologia) and the Fundo Social Europeu através do Programa Operacional do Capital Humano (FSE/POCH) in the framework of Ph.D. grants PD/BD/113807/2015 (BBM) and PD/BD/129403/2017 (SMB), Post-Doc grant SFRH/ BPD/112459/2015 (RMD) and project SmarTendon (PTDC/NAN-MAT/30595/2017); Project NORTE01-0145-FEDER-000021 supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF

Cellulose nanocrystals of variable sulfation degrees can sequester specific platelet lysate-derived biomolecules to modulate stem cell response

The surface chemistry of cellulose nanocrystals was engineered to show variable sulfation degrees, which was exploited to modulate platelet lysate-derived biomolecule sequestration and presentation. The protein coronas developed on CNC surfaces were characterized and it was demonstrated how they promote different signaling effects on human adipose-derived stem cell behavior.The research has received funding from PTDC/NAN-MAT/30595/2017, ERC Grant No. 772817; FCT/MCTES for PD/59/2013 - PD/BD/113807/2015, for ITI Research grant 1306_2018,ROTEIRO/0028/2013, and LISBOA-01-0145-FEDER-022125

Xeno-free bioengineered human skeletal muscle tissue using human platelet lysate-based hydrogels

Bioengineered human skeletal muscle tissues have emerged in the last years as new in vitro systems for disease modeling. These bioartificial muscles are classically fabricated by encapsulating human myogenic precursor cells in a hydrogel scaffold that resembles the extracellular matrix. However, most of these hydrogels are derived from xenogenic sources, and the culture media is supplemented with animal serum, which could interfere in drug testing assays. On the contrary, xeno-free biomaterials and culture conditions in tissue engineering offer increased relevance for developing human disease models. In this work, we used human platelet lysate (PL)-based nanocomposite hydrogels (HUgel) as scaffolds for human skeletal muscle tissue engineering. These hydrogels consist of human PL reinforced with aldehyde-cellulose nanocrystals (a-CNC) that allow tunable mechanical, structural, and biochemical properties for the 3D culture of stem cells. Here, we developed hydrogel casting platforms to encapsulate human muscle satellite stem cells in HUgel. The a-CNC content was modulated to enhance matrix remodeling, uniaxial tension, and self-organization of the cells, resulting in the formation of highly aligned, long myotubes expressing sarcomeric proteins. Moreover, the bioengineered human muscles were subjected to electrical stimulation, and the exerted contractile forces were measured in a non-invasive manner. Overall, our results demonstrated that the bioengineered human skeletal muscles could be built in xeno-free cell culture platforms to assess tissue functionality, which is promising for drug development applications.The authors thank the technical support of MicroFabSpace and Microscopy Characterization Facility, Unit 7 of ICTS 'NANBIOSIS' from CIBER-BBN at IBEC. We would also like to thank the muscle team from the Biosensors for Bioengineering group for their feedback in the review process of this manuscript. Human immortalized muscle satellite stem cells used in this study were kindly provided by Dr Bénédicte Chazaud (Institut NeuroMyoGène (INMG), Lyon, France). This project received financial support from European Research Council program Grant ERC-StG-DAMOC: 714317 (J R-A), European Commission under FET-open program BLOC Project: GA- 863037 (J R-A), Spanish Ministry of Economy and Competitiveness, through the 'Severo Ochoa' Program for Centres of Excellence in R&D: SEV-2016–2019, Spanish Ministry of Economy and Competitiveness: 'Retos de investigación: Proyectos I+D+i': TEC2017-83716-C2-2-R (J R-A), CERCA Programme/Generalitat de Catalunya: 2017-SGR-1079 (J R-A), and Fundación Bancaria 'la Caixa'- Obra Social 'la Caixa': project IBEC-La Caixa Healthy Ageing (J R-A). The authors also acknowledge the European Union's Horizon 2020 research and innovation program under European Research Council Grant Agreement 772817 and Twinning Grant Agreement No. 810850—Achilles. Fundação para a Ciência e a Tecnologia (FCT) for CEECIND/01375/2017 (M G-F) and 2020.03410.CEECIND (R M A D)

Bioengineered 3D living fibers as in vitro human tissue models of tendon physiology and pathology

Clinically relevant in vitro models of human tissue's health and disease are urgently needed for a better understanding of biological mechanisms essential for the development of novel therapies. Herein, physiological (healthy) and pathological (disease) tendon states are bioengineered by coupling the biological signaling of platelet lysate components with controlled 3D architectures of electrospun microfibers to drive the fate of human tendon cells in different composite living fibers (CLFs). In the CLFs-healthy model, tendon cells adopt a high cytoskeleton alignment and elongation, express tendon-related markers (scleraxis, tenomodulin, and mohawk) and deposit a dense tenogenic matrix. In contrast, cell crowding with low preferential orientation, high matrix deposition, and phenotypic drift leading to increased expression of nontendon related and fibrotic markers, are characteristics of the CLFs-diseased model. This diseased-like profile, also reflected in the increase of COL3/COL1 ratio, is further evident by the imbalance between matrix remodeling and degradation effectors, characteristic of tendinopathy. In summary, microengineered 3D in vitro models of human tendon healthy and diseased states are successfully fabricated. Most importantly, these innovative and versatile microphysiological models offer major advantages over currently used systems, holding promise for drugs screening and development of new therapies.Work developed under the framework of the Cooperation Agreement established with the Serviço de Imuno-Hemoterapia do Centro Hospitalar de S. João, EPE. The authors would like to thank the Plastic Surgery Department of Hospital da Prelada (Porto, Portugal) for providing tendon tissue samples. Authors acknowledge the financial support from the ERC Grant CoG MagTendon No. 772817; FCT– Fundação para a Ciência e a Tecnologia for the Ph.D. grant of IC (PD/BD/128088/2016) and CL (PD/BD/150515/2019); for the contract to M.G.F. (CEECIND/01375/2017); and for project SmarTendon (PTDC/NAN-MAT/30595/2017) and Achilles (Grant no. 810850). After ini tial online publication, the present address for D.D. was added to the af filiations section on August 3, 2022

Natural-based hydrogels for tissue engineering applications

In the field of tissue engineering and regenerative medicine, hydrogels are used as biomaterials to support cell attachment and promote tissue regeneration due to their unique biomimetic characteristics. The use of natural-origin materials significantly influenced the origin and progress of the field due to their ability to mimic the native tissuesâ extracellular matrix and biocompatibility. However, the majority of these natural materials failed to provide satisfactory cues to guide cell differentiation toward the formation of new tissues. In addition, the integration of technological advances, such as 3D printing, microfluidics and nanotechnology, in tissue engineering has obsoleted the first generation of natural-origin hydrogels. During the last decade, a new generation of hydrogels has emerged to meet the specific tissue necessities, to be used with state-of-the-art techniques and to capitalize the intrinsic characteristics of natural-based materials. In this review, we briefly examine important hydrogel crosslinking mechanisms. Then, the latest developments in engineering natural-based hydrogels are investigated and major applications in the field of tissue engineering and regenerative medicine are highlighted. Finally, the current limitations, future challenges and opportunities in this field are discussed to encourage realistic developments for the clinical translation of tissue engineering strategies.Authors acknowledge financial support from the European Union Framework Programme for Research and Innovation Horizon 2020 under European Research Council grant agreement No. 772817; FCT (Fundação para a Ciência e a Tecnologia) for individual fellowship CEECIND/01375/2017 (MGF); FCT for project PTDC/NAN-MAT/30595/2017; Xunta de Galicia for postdoctoral fellowship ED481B-2019-025 (AP); Norwegian Research Council (NFR) for project No. 287953

Tropoelastin coated tendon biomimetic scaffolds promote stem cell tenogenic commitment and deposition of elastin-rich matrix

Tendon tissue engineering strategies that recreate the biophysical and biochemical native microenvironment have a greater potential to achieve regeneration. Here, we developed tendon biomimetic scaffolds using mechanically competent yarns of poly-ε-caprolactone, chitosan and cellulose nanocrystals to recreate the inherent tendon hierarchy from the nano to macro scale. These were then coated with tropoelastin (TROPO) through polydopamine linking (PDA), to mimic the native extracellular matrix (ECM) composition and elasticity. Both PDA and TROPO coatings decreased surface stiffness without masking the underlying substrate. We found that human adipose-derived stem cells (hASCs) seeded onto these TROPO biomimetic scaffolds more rapidly acquired their spindle-shape morphology and high aspect ratio characteristic of tenocytes. Immunocytochemistry shows that the PDA and TROPO-coated surfaces boosted differentiation of hASCs towards the tenogenic lineage, with sustained expression of the tendon-related markers scleraxis and tenomodulin up to 21 days of culture. Furthermore, these surfaces enabled the deposition of a tendon-like ECM, supported by the expression of collagens type I and III, tenascin and decorin. Gene expression analysis revealed a downregulation of osteogenic and fibrosis markers in the presence of TROPO when compared with the control groups, suggesting proper ECM deposition. Remarkably, differentiated cells exposed to TROPO acquired an elastogenic profile due to the evident elastin synthesis and deposition, contributing to the formation of a more mimetic matrix in comparison with the PDA-coated and uncoated conditions. In summary, our biomimetic substrates combining biophysical and biological cues modulate stem cell behavior potentiating their long-term tenogenic commitment and the production of an elastin-rich ECM.European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 706996, Teaming grant agreement No 739572 – The Discoveries CTR, European Research Council grant agreement No 726178, and ERA Chair grant agreement No 668983 - FORECAST; Biomedical Engineering Australian Mobility (BEAM) Program – Master Joint Mobility Project between EU Commission Australian Government; Fundação para a Ciência e a Tecnologia (FCT) for Post-Doc grant SFRH/BPD/112459/2015 and project SmarTendon (PTDC/NAN-MAT/30595/2017); Norte Portugal Regional Operational Program (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund for NORTE-01-0145-FEDER-00002

Intrinsically bioactive cryogels based on platelet lysate nanocomposites for hemostasis applications.

The currently used hemostatic agents are highly effective in stopping hemorrhages but have a limited role in the modulation of the wound-healing environment. Herein, we propose an intrinsically bioactive hemostatic cryogel based on platelet lysate (PL) and aldehyde-functionalized cellulose nanocrystals (a-CNCs). PL has attracted great attention as an inexpensive milieu of therapeutically relevant proteins; however, its application as a hemostatic agent exhibits serious constraints (e.g., structural integrity and short shelf-life). The incorporation of a-CNCs reinforced the low-strength PL matrix by covalent cross-linking its amine groups that exhibit an elastic interconnected porous network after full cryogelation. Upon blood immersion, the PL-CNC cryogels absorbed higher volumes of blood at a faster rate than commercial hemostatic porcine gelatin sponges. Simultaneously, the cryogels released biomolecules that increased stem cell proliferation, metabolic activity, and migration as well as downregulated the expression of markers of the fibrinolytic process. In an in vivo liver defect model, PL-CNC cryogels showed similar hemostatic performance in comparison with gelatin sponges and normal material-induced tissue response upon subcutaneous implantation. Overall, owing to their structure and bioactive composition, the proposed PL-CNC cryogels provide an alternative off-the-shelf hemostatic and antibacterial biomaterial with the potential to deliver therapeutically relevant proteins in situ.The authors thank Hospital da Prelada (Porto, Portugal) for providing adipose tissue samples and Instituto Portugues do Sangue e Transplantacio-IPST (Portugal) (Porto, Portugal) for providing platelet concentrates. The authors would like to thank Alain Morais and Isabel Pires for their support in the in vivo procedure and histological evaluation, respectively. The authors would like to thank the anonymous reviewers for all useful and helpful comments on our manuscript. This work was supported by the European Research Council grant agreement no. 772817, FCT/MCTES (Fundacio para a Ciencia e a Tecnologia/Ministerio da Ciencia, Tecnologia, e Ensino Superior) and the Fundo Social Europeu atraves do Programa Operacional do Capital Humano (FSE/POCH) in the framework of Ph.D. grant PD/59/2013-PD/BD/113807/2015 (BBM) and CEECIND/01375/2017 (MGF), Norwegian Research Council for project no. 287953

Human-based nanocomposite cryogels for hemostatic and wound healing applications

In trauma surgery, a fast and effective hemostatic agent is crucial to prevent death. The current used hemostatic sponges are highly effective in stopping the hemorrhages, however they have a limited stability, shape memory, and biological functionality to induce an efficient regenerative healing after injury. Blood derivatives have attracted great attention as an inexpensive milieu of bioactive molecules (e.g., growth factors, cytokines), self-assembling scaffolding proteins (e.g., fibrinogen, fibronectin, vitronectin), and antimicrobial peptides (e.g., platelet factor-4) that have the ability to enhance angiogenesis, stem cell recruitment, and tissue regeneration. Among those, platelet lysate (PL) has attracted great attention as a milieu of supra-physiological doses of biomolecules that can be easily standardized. However, the current PL scaffolds showed limited stability and weak mechanical strength, which severely limits its performance as a bioinstructive and hemostatic biomaterial. Herein, we propose the use of aldehyde-functionalized CNC (a-CNC) that will be crosslinked through reversible Schiff base bonds established with the amine groups of PL proteins to produce a stable hemostatic cryogel for wound healing applications.EU’s H2020 programme for grant agreement 706996 and 739572 - The Discoveries CTR; FCT for SFRH/BPD/112459/2015, PD/BD/113807/2015, FOOD4CELLS (PTDC/CTM-BIO/4706/2014-POCI-01- 0145- FEDER 016716) and project NORTE-01-0145- FEDER-000021