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1.
Breast Cancer ; 30(4): 559-569, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36977972

ABSTRACT

BACKGROUND: Based on the volume of tissue removed, conservative surgery (BCS) cannot always guarantee satisfactory cosmetic results, unless resorting to more complex oncoplastic approaches. Investigating an alternative to optimize aesthetic outcomes minimizing surgical complexity, was the purpose of this study. We assessed an innovative surgical procedure based on the use of a biomimetic polyurethane-based scaffold intended for regenerating soft-tissue resembling fat, in patients undergoing BCS for non-malignant breast lesions. Safety and performance of the scaffold, and safety and feasibility of the entire implant procedure were evaluated. METHODS: A volunteer sample of 15 female patients underwent lumpectomy with immediate device positioning, performing seven study visits with six-month follow-up. We evaluated incidence of adverse events (AEs), changes in breast appearance (using photographs and anthropomorphic measurements), interference with ultrasound and MRI (assessed by two independent investigators), investigator's satisfaction (through a VAS scale), patient's pain (through a VAS scale) and quality of life (QoL) (using the BREAST-Q© questionnaire). Data reported are the results of the interim analysis on the first 5 patients. RESULTS: No AEs were device related nor serious. Breast appearance was unaltered and the device did not interference with imaging. High investigator's satisfaction, minimal post-operative pain and positive impact on QoL were also detected. CONCLUSIONS: Albeit on a limited number of patients, data showed positive outcomes both in terms of safety and performance, paving the way to an innovative breast reconstructive approach with a potential remarkable impact on clinical application of tissue engineering. TRIAL REGISTRATION: ClinicalTrials.gov (NCT04131972, October 18, 2019).


Subject(s)
Breast Neoplasms , Mammaplasty , Mastectomy, Segmental , Female , Humans , Biomimetics , Breast Neoplasms/surgery , Mammaplasty/adverse effects , Mammaplasty/methods , Patient Satisfaction , Polyurethanes , Quality of Life , Mastectomy, Segmental/adverse effects , Tissue Scaffolds , Tissue Engineering
2.
Anal Chim Acta ; 1239: 340710, 2023 Jan 25.
Article in English | MEDLINE | ID: mdl-36628716

ABSTRACT

The new challenge in the investigation of cultural heritage is the possibility to obtain stratigraphical information about the distribution of the different organic and inorganic components without sampling. In this paper recently commercialized analytical set-up, which is able to co-register VNIR, SWIR, and XRF spectral data simultaneously, is exploited in combination with an innovative multivariate and multiblock high-throughput data processing for the analysis of multilayered paintings. The instrument allows to obtain elemental and molecular information from superficial to subsurface layers across the investigated area. The chemometric strategy proved to be highly efficient in data reduction and for the extraction and integration of the most useful information coming from the three different spectroscopies, also filling the gap between data acquisition and data understanding through the combination of principal component analysis (PCA), brushing, correlation diagrams and maps (within and between spectral blocks) on the low-level fused. In particular, correlation diagrams and maps provide useful information for the reconstruction of a stratigraphic structure without the need to take any sample, thanks to the effective account for inter-correlation among data (variables), which is able to effectively characterize the possible combinations of components located in the same depth level. The highly innovative technology and the data processing strategy are applied for the multi-level characterization of a complex painting reproduction as an illustrative pilot study.


Subject(s)
Hyperspectral Imaging , Paintings , Pilot Projects , Principal Component Analysis , Chemometrics
3.
Sci Rep ; 11(1): 13310, 2021 06 25.
Article in English | MEDLINE | ID: mdl-34172806

ABSTRACT

The use of cell-free scaffolds for the regeneration of clinically relevant volumes of soft tissue has been challenged, particularly in the case of synthetic biomaterials, by the difficulty of reconciling the manufacturing and biological performance requirements. Here, we investigated in vivo the importance of biomechanical and biochemical cues for conditioning the 3D regenerative microenvironment towards soft tissue formation. In particular, we evaluated the adipogenesis changes related to 3D mechanical properties by creating a gradient of 3D microenvironments with different stiffnesses using 3D Poly(Urethane-Ester-ether) PUEt scaffolds. Our results showed a significant increase in adipose tissue proportions while decreasing the stiffness of the 3D mechanical microenvironment. This mechanical conditioning effect was also compared with biochemical manipulation by loading extracellular matrices (ECMs) with a PPAR-γ activating molecule. Notably, results showed mechanical and biochemical conditioning equivalency in promoting adipose tissue formation in the conditions tested, suggesting that adequate mechanical signaling could be sufficient to boost adipogenesis by influencing tissue remodeling. Overall, this work could open a new avenue in the design of synthetic 3D scaffolds for microenvironment conditioning towards the regeneration of large volumes of soft and adipose tissue, with practical and direct implications in reconstructive and cosmetic surgery.


Subject(s)
Cellular Microenvironment/physiology , Regeneration/physiology , 3T3-L1 Cells , Adipogenesis/physiology , Adipose Tissue/physiology , Animals , Cell Line , Extracellular Matrix/physiology , Mice , Tissue Engineering/methods , Tissue Scaffolds/chemistry , Wound Healing/physiology
4.
Adv Sci (Weinh) ; 6(6): 1802045, 2019 Mar 20.
Article in English | MEDLINE | ID: mdl-30937270

ABSTRACT

The ability to cryopreserve natural killer (NK) cells has a significant potential in modern cancer immunotherapy. Current cryopreservation protocols cause deterioration in NK cell viability and functionality. This work reports the preservation of human cytokine-activated NK cell viability and function following cryopreservation using a cocktail of biocompatible bioinspired cryoprotectants (i.e., dextran and carboxylated ε-poly-L-lysine). Results demonstrate that the recovered NK cells after cryopreservation and rewarming maintain their viability immediately after thawing at a comparable level to control (dimethyl sulfoxide-based cryopreservation). Although, their viability drops in the first day in culture compared to controls, the cells grow back to a comparable level to controls after 1 week in culture. In addition, the anti-tumor functional activity of recovered NK cells demonstrates higher cytotoxic potency against leukemia cells compared to control. This approach presents a new direction for NK cell preservation, focusing on function and potentially enabling storage and distribution for cancer immunotherapy.

5.
Biomaterials ; 197: 171-181, 2019 03.
Article in English | MEDLINE | ID: mdl-30660993

ABSTRACT

The replication of the complex structure and three dimensional (3-D) interconnectivity of neurons in the brain is a great challenge. A few 3-D neuronal patterning approaches have been developed to mimic the cell distribution in the brain but none have demonstrated the relationship between 3-D neuron patterning and network connectivity. Here, we used photolithographic crosslinking to fabricate in vitro 3-D neuronal structures with distinct sizes, shapes or interconnectivities, i.e., milli-blocks, micro-stripes, separated micro-blocks and connected micro-blocks, which have spatial confinement from "Z" dimension to "XYZ" dimension. During a 4-week culture period, the 3-D neuronal system has shown high cell viability, axonal, dendritic, synaptic growth and neural network activity of cortical neurons. We further studied the calcium oscillation of neurons in different 3-D patterns and used signal processing both in Fast Fourier Transform (FFT) and time domain (TD) to model the fluorescent signal variation. We observed that the firing frequency decreased as the spatial confinement in 3-D system increased. Besides, the neuronal synchronization significantly decreased by irregularly connecting micro-blocks, indicating that network connectivity can be adjusted by changing the linking conditions of 3-D gels. Earlier works showed the importance of 3-D culture over 2-D in terms of cell growth. Here, we showed that not only 3-D geometry over 2-D culture matters, but also the spatial organization of cells in 3-D dictates the neuronal firing frequency and synchronicity.


Subject(s)
Cell Culture Techniques/methods , Nerve Net/physiology , Neurons/physiology , Action Potentials , Animals , Biocompatible Materials/chemistry , Calcium Signaling , Cells, Cultured , Cerebral Cortex/cytology , Cerebral Cortex/physiology , Hydrogels/chemistry , Mice , Nerve Net/cytology , Neurons/cytology , Tissue Scaffolds/chemistry
6.
Biomaterials ; 181: 402-414, 2018 10.
Article in English | MEDLINE | ID: mdl-30138793

ABSTRACT

Organized networks are common in nature showing specific tissue micro-architecture, where cells can be found isotropically or anisotropically distributed in characteristic arrangements and tissue stiffness. However, when addressing an in vitro tissue model, it is challenging to grant control over mechanical properties while achieving anisotropic porosity of polymeric networks, especially in three-dimensional systems (3-D). While progress was achieved organizing cells in two-dimension (2-D), fabrication methods for aligned networks in 3-D are limited. Here, we describe the use of a biomimetic extra-cellular matrix system allowing programming of anisotropic structures into precisely advancing pore diameters in 3-D. Using control over polymeric composition, crosslinking directionality and freezing gradient dynamics, we revealed a mechanism to top-down biofabricate 3-D structures with tunable micro-porosity capable of directing cellular responses at millimeter scale such as axonal anisotropic outgrowth that is a unique characteristic of the brain cortex. Further, we showed the unique integration of this method with a microfluidic system establishing a neural-endothelial heterotypic conjugation, which can potentially be broadly applied to multiple organ systems.


Subject(s)
Anisotropy , Nerve Tissue/cytology , Tissue Scaffolds/chemistry , Animals , Cell Survival/physiology , Cerebral Cortex/cytology , Human Umbilical Vein Endothelial Cells , Humans , Mice, Inbred C57BL , Microfluidics/methods , Tissue Engineering/methods
7.
Acta Biomater ; 73: 154-166, 2018 06.
Article in English | MEDLINE | ID: mdl-29684623

ABSTRACT

Fat grafting is emerging as a promising alternative to silicon implants in breast reconstruction surgery. Unfortunately, this approach does not provide a proper mechanical support and is affected by drawbacks such as tissue resorption and donor site morbidity. Synthetic scaffolds can offer a valuable alternative to address these challenges, but poorly recapitulate the biochemical stimuli needed for tissue regeneration. Here, we aim at combining the positive features of a structural, synthetic polymer to an engineered, devitalized extracellular matrix (ECM) to generate a hybrid construct that can provide a mix of structural and biological stimuli needed for adipose tissue regeneration. A RGD-mimetic synthetic scaffold OPAAF, designed for soft tissue engineering, was decorated with ECM deposited by human adipose stromal cells (hASCs). The adipoinductive potential of the hybrid ECM-OPAAF construct was validated in vitro, by culture with hASC in a perfusion bioreactor system, and in vivo, by subcutaneous implantation in nude mouse. Our findings demonstrate that the hybrid ECM-OPAAF provides proper mechanical support and adipoinductive stimuli, with potential applicability as off-the-shelf material for adipose tissue reconstruction. STATEMENT OF SIGNIFICANCE: In this study we combined the functionalities of a synthetic polymer with those of an engineered and subsequently devitalized extracellular matrix (ECM) to generate a hybrid material for adipose tissue regeneration. The developed hybrid ECM-OPAAF was demonstrated to regulate human adipose stromal cells adipogenic commitment in vitro and adipose tissue infiltration in vivo. Our findings demonstrate that the hybrid ECM-OPAAF provide proper mechanical support and adipoinductive stimuli and represents a promising off-the-shelf material for adipose tissue reconstruction. We believe that our approach could offer an alternative strategy for adipose tissue reconstruction in case of mastectomy or congenital abnormalities, overcoming the current limitations of autologous fat based strategies such as volume resorption and donor site morbidity.


Subject(s)
Adipose Tissue/physiology , Biomimetic Materials , Extracellular Matrix/chemistry , Oligopeptides , Regeneration/drug effects , Tissue Scaffolds/chemistry , Biomimetic Materials/chemistry , Biomimetic Materials/pharmacology , Humans , Oligopeptides/chemistry , Oligopeptides/pharmacology , Porosity
8.
Acta Biomater ; 73: 141-153, 2018 06.
Article in English | MEDLINE | ID: mdl-29654992

ABSTRACT

Reconstructive treatment after trauma and tumor resection would greatly benefit from an effective soft tissue regeneration. The use of cell-free scaffolds for adipose tissue regeneration in vivo is emerging as an attractive alternative to tissue-engineered constructs, since this approach avoids complications due to cell manipulation and lack of synchronous vascularization. In this study, we developed a biodegradable polyurethane-based scaffold for soft tissue regeneration, characterized by an exceptional combination between softness and resilience. Exploring the potential as a cell-free scaffold required profound understanding of the impact of its intrinsic physico-chemical properties on the biological performance in vivo. We investigated the effect of the scaffold's hydrophilic character, degradation kinetics, and internal morphology on (i) the local inflammatory response and activation of MGCs (foreign body response); (ii) its ability to promote rapid vascularisation, cell infiltration and migration through the scaffold over time; and (iii) the grade of maturation of the newly formed tissue into vascularized soft tissue in a murine model. The study revealed that soft tissue regeneration in vivo proceeded by gradual infiltration of undifferentiated mesenchymal cells though the periphery toward the center of the scaffold, where the rapid formation of a functional and well-formed vascular network supported cell viability overtime. STATEMENT OF SIGNIFICANCE: Exploring the potential of polyurethane-based soft foam as cell-free scaffold for soft tissue regeneration. In this work, we address the unmet need for synthetic functional soft tissue substitutes that provide adequate biological and mechanical support to soft tissue. We developed a series of flexible cross-linked polyurethane copolymer scaffolds with remarkable fatigue-resistance and tunable physico-chemical properties for soft tissue regeneration in vivo. Accordingly, we could extend the potential of this class of biomaterials, which was so far confined for bone and osteochondral tissue regeneration, to other types of connective tissue.


Subject(s)
Adipose Tissue/blood supply , Neovascularization, Physiologic/drug effects , Polyurethanes , Regeneration/drug effects , Tissue Scaffolds/chemistry , Adipose Tissue/pathology , Animals , Mice , NIH 3T3 Cells , Polyurethanes/chemistry , Polyurethanes/pharmacology
9.
Adv Mater ; 30(4)2018 Jan.
Article in English | MEDLINE | ID: mdl-29215164

ABSTRACT

In nature, cells self-assemble at the microscale into complex functional configurations. This mechanism is increasingly exploited to assemble biofidelic biological systems in vitro. However, precise coding of 3D multicellular living materials is challenging due to their architectural complexity and spatiotemporal heterogeneity. Therefore, there is an unmet need for an effective assembly method with deterministic control on the biomanufacturing of functional living systems, which can be used to model physiological and pathological behavior. Here, a universal system is presented for 3D assembly and coding of cells into complex living architectures. In this system, a gadolinium-based nonionic paramagnetic agent is used in conjunction with magnetic fields to levitate and assemble cells. Thus, living materials are fabricated with controlled geometry and organization and imaged in situ in real time, preserving viability and functional properties. The developed method provides an innovative direction to monitor and guide the reconfigurability of living materials temporally and spatially in 3D, which can enable the study of transient biological mechanisms. This platform offers broad applications in numerous fields, such as 3D bioprinting and bottom-up tissue engineering, as well as drug discovery, developmental biology, neuroscience, and cancer research.


Subject(s)
Tissue Engineering , Bioprinting
10.
Nat Biotechnol ; 35(6): 530-542, 2017 06 07.
Article in English | MEDLINE | ID: mdl-28591112

ABSTRACT

The ability to replace organs and tissues on demand could save or improve millions of lives each year globally and create public health benefits on par with curing cancer. Unmet needs for organ and tissue preservation place enormous logistical limitations on transplantation, regenerative medicine, drug discovery, and a variety of rapidly advancing areas spanning biomedicine. A growing coalition of researchers, clinicians, advocacy organizations, academic institutions, and other stakeholders has assembled to address the unmet need for preservation advances, outlining remaining challenges and identifying areas of underinvestment and untapped opportunities. Meanwhile, recent discoveries provide proofs of principle for breakthroughs in a family of research areas surrounding biopreservation. These developments indicate that a new paradigm, integrating multiple existing preservation approaches and new technologies that have flourished in the past 10 years, could transform preservation research. Capitalizing on these opportunities will require engagement across many research areas and stakeholder groups. A coordinated effort is needed to expedite preservation advances that can transform several areas of medicine and medical science.


Subject(s)
Cryopreservation/trends , Organ Culture Techniques/trends , Organ Preservation/trends , Organ Transplantation/trends , Regenerative Medicine/trends , Forecasting , Humans , Tissue Preservation/trends
11.
Colloids Surf B Biointerfaces ; 151: 197-205, 2017 Mar 01.
Article in English | MEDLINE | ID: mdl-28013163

ABSTRACT

This study presents an innovative method for the synthesis of polymeric nanoparticles (NPs) for central nervous system (CNS) targeting. The method is based on Ultraviolet light (UV)-induced crosslinking of diacrylamide-terminated oligomers of poly(amidoamine)s (PAAs), a widely used class of synthetic polymers in biomedical field research, especially in drug delivery thanks to their excellent biocompatibility and controlled biodegradability. Previous attempts aiming at preparing PAA-based NPs by self-assembly were challenged by lack of structural stability and consequently their early degradation and premature drug release. Here, the UV-induced crosslinked PAA NPs demonstrated to overcome main disadvantages of the self-assembled ones, as they showed improved stability and controlled release properties. Besides the remarkable efficiency to produce monodisperse and stable PAA NPs, the UV-induced crosslinking method is featured by great versatility and low environmental impact, since it does not require use of organic solvents and multiple purification steps. The capability of PAA NPs to encapsulate a fluorescently labelled model protein was experimentally demonstrated in this study. Cell culture experiments showed that PAA NPs were biocompatible and highly permeable across an in vitro blood-brain barrier model, thus highlighting their great potential as drug delivery vectors for CNS delivery.


Subject(s)
Central Nervous System/drug effects , Cross-Linking Reagents/chemistry , Drug Carriers/chemistry , Nanoparticles/chemistry , Photochemistry/methods , Polyamines/chemistry , Animals , Biocompatible Materials/chemistry , Blood-Brain Barrier , Brain/metabolism , Carbocyanines/chemistry , Drug Delivery Systems , Human Umbilical Vein Endothelial Cells , Humans , Immunoglobulin G/chemistry , Light , Mice , Microscopy, Fluorescence , Permeability , Polymers/chemistry , Scattering, Radiation , Serum Albumin/chemistry , Solvents/chemistry , Ultraviolet Rays
12.
J Tissue Eng Regen Med ; 11(1): 187-196, 2017 01.
Article in English | MEDLINE | ID: mdl-24799388

ABSTRACT

Loss of skeletal muscle tissue caused by traumatic injury or damage due to myopathies produces a deficit of muscle function for which there is still no clinical treatment. Transplantation of myogenic cells, themselves or combined with materials, has been proposed to increase the regenerative capacity of skeletal muscle but it is hampered by many limitations, such as low cell survival and engraftment or immunological reaction and low biocompatibility of the exogenous materials. Recently, myoblast sheet engineering, obtained with thermoresponsive culture dishes, has attracted attention as a new technique for muscle damage treatment. For this purpose, a series of thermoresponsive hydrogels, constituted by poly(N-isopropylacrylamide-co-2-hydroxyethylmethacrylate) [p(NIPAAM-co-HEMA)] were synthesized by a simple and inexpensive free-radical polymerization of the two co-monomers with a redox initiator. Different ratios of N-isopropylacrylamide (NIPAAm) and 2-hydroxyethylmethacrylate (HEMA) have been examined to evaluate the effects on physicochemical, mechanical and optical hydrogel properties. The murine muscle cell line C2 C12 has been exploited to test the cytotoxicity of the thermoresponsive hydrogels, depending on different synthesis conditions. In this study, we have identified a thermoresponsive hydrogel that allows cell adhesion and viability, together with the detachment of viable sheet of muscle cells, giving the chance to develop further applications for muscle damage and disease. Copyright © 2014 John Wiley & Sons, Ltd.


Subject(s)
Acrylamides/chemistry , Biocompatible Materials/chemistry , Hydrogels/chemistry , Methacrylates/chemistry , Myoblasts/cytology , Tissue Engineering/methods , Animals , Calorimetry, Differential Scanning , Cell Adhesion , Cell Line , Cell Proliferation , Compressive Strength , Glass/chemistry , Materials Testing , Mice , Polymers/chemistry , Silanes/chemistry , Spectroscopy, Fourier Transform Infrared , Temperature
13.
Sci Rep ; 6: 39144, 2016 12 22.
Article in English | MEDLINE | ID: mdl-28004818

ABSTRACT

Cancer cells have been increasingly grown in pharmaceutical research to understand tumorigenesis and develop new therapeutic drugs. Currently, cells are typically grown using two-dimensional (2-D) cell culture approaches, where the native tumor microenvironment is difficult to recapitulate. Thus, one of the main obstacles in oncology is the lack of proper infection models that recount main features present in tumors. In recent years, microtechnology-based platforms have been employed to generate three-dimensional (3-D) models that better mimic the native microenvironment in cell culture. Here, we present an innovative approach to culture Kaposi's sarcoma-associated herpesvirus (KSHV) infected human B cells in 3-D using a microwell array system. The results demonstrate that the KSHV-infected B cells can be grown up to 15 days in a 3-D culture. Compared with 2-D, cells grown in 3-D had increased numbers of KSHV latency-associated nuclear antigen (LANA) dots, as detected by immunofluorescence microscopy, indicating a higher viral genome copy number. Cells in 3-D also demonstrated a higher rate of lytic reactivation. The 3-D microwell array system has the potential to improve 3-D cell oncology models and allow for better-controlled studies for drug discovery.


Subject(s)
Antigens, Viral/genetics , B-Lymphocytes/virology , Cell Culture Techniques/instrumentation , Gene Expression Regulation, Viral , Herpesvirus 8, Human/physiology , Nuclear Proteins/genetics , Antigens, Viral/metabolism , Cell Line, Tumor , Humans , Nuclear Proteins/metabolism , Viral Load , Virus Activation , Virus Latency/genetics
14.
Biomaterials ; 104: 65-77, 2016 10.
Article in English | MEDLINE | ID: mdl-27428768

ABSTRACT

Despite clinical treatments for adipose tissue defects, in particular breast tissue reconstruction, have certain grades of efficacy, many drawbacks are still affecting the long-term survival of new formed fat tissue. To overcome this problem, in the last decades, several scaffolding materials have been investigated in the field of adipose tissue engineering. However, a strategy able to recapitulate a suitable environment for adipose tissue reconstruction and maintenance is still missing. To address this need, we adopted a biologically and mechanically driven design to fabricate an RGD-mimetic poly(amidoamine) oligomer macroporous foam (OPAAF) for adipose tissue reconstruction. The scaffold was designed to fulfil three fundamental criteria: capability to induce cell adhesion and proliferation, support of in vivo vascularization and match of native tissue mechanical properties. Poly(amidoamine) oligomers were formed into soft scaffolds with hierarchical porosity through a combined free radical polymerization and foaming reaction. OPAAF is characterized by a high water uptake capacity, progressive degradation kinetics and ideal mechanical properties for adipose tissue reconstruction. OPAAF's ability to support cell adhesion, proliferation and adipogenesis was assessed in vitro using epithelial, fibroblast and endothelial cells (MDCK, 3T3L1 and HUVEC respectively). In addition, in vivo subcutaneous implantation in murine model highlighted OPAAF potential to support both adipogenesis and vessels infiltration. Overall, the reported results support the use of OPAAF as a scaffold for engineered adipose tissue construct.


Subject(s)
Adipocytes/physiology , Adipogenesis/physiology , Adipose Tissue/growth & development , Mechanotransduction, Cellular/physiology , Oligopeptides/chemistry , Tissue Scaffolds , Adipocytes/cytology , Adipose Tissue/cytology , Animals , Biomimetic Materials/chemical synthesis , Cell Adhesion/physiology , Cell Line , Cell Proliferation/physiology , Compressive Strength , Elastic Modulus , Extracellular Matrix/chemistry , Female , Gases/chemistry , Mice , Neovascularization, Physiologic/physiology , Porosity , Stress, Mechanical , Tissue Engineering/instrumentation , Tissue Engineering/methods
15.
Macromol Biosci ; 16(6): 870-81, 2016 06.
Article in English | MEDLINE | ID: mdl-26900107

ABSTRACT

This study presents a custom-made in situ gelling polymeric precursor for cell encapsulation. Composed of poly((2-hydroxyethyl)methacrylate-co-(3-aminopropyl)methacrylamide) (P(HEMA-co-APM) mother backbone and RGD-mimicking poly(amidoamine) (PAA) moiteis, the comb-like structured polymeric precursor is tailored to gather the advantages of the two families of synthetic polymers, i.e., the good mechanical integrity of PHEMA-based polymers and the biocompatibility and biodegradability of PAAs. The role of P(HEMA-co-APM) in the regulation of the chemico-physical properties of P(HEMA-co-APM)/PAA hydrogels is thoroughly investigated. On the basis of obtained results, namely the capability of maintaining vital NIH3T3 cell line in vitro for 2 d in a 3D cell culture, the in vivo biocompatibility in murine model for 16 d, and the ability of finely tuning mechanical properties and degradation kinetics, it can be assessed that P(HEMA-co-APM)/PAAs offer a cost-effective valid alternative to the so far studied natural polymer-based systems for cell encapsulation.


Subject(s)
Alanine/analogs & derivatives , Hydrogels/chemistry , Polyhydroxyethyl Methacrylate/chemistry , Acrylamides/chemistry , Alanine/chemistry , Alanine/pharmacology , Animals , Cell Culture Techniques/methods , Hydrogels/pharmacology , Kinetics , Materials Testing , Methacrylates/chemistry , Mice , NIH 3T3 Cells/drug effects , Polyhydroxyethyl Methacrylate/pharmacology
16.
Cryobiology ; 72(2): 169-82, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26687388

ABSTRACT

The first Organ Banking Summit was convened from Feb. 27 - March 1, 2015 in Palo Alto, CA, with events at Stanford University, NASA Research Park, and Lawrence Berkeley National Labs. Experts at the summit outlined the potential public health impact of organ banking, discussed the major remaining scientific challenges that need to be overcome in order to bank organs, and identified key opportunities to accelerate progress toward this goal. Many areas of public health could be revolutionized by the banking of organs and other complex tissues, including transplantation, oncofertility, tissue engineering, trauma medicine and emergency preparedness, basic biomedical research and drug discovery - and even space travel. Key remaining scientific sub-challenges were discussed including ice nucleation and growth, cryoprotectant and osmotic toxicities, chilling injury, thermo-mechanical stress, the need for rapid and uniform rewarming, and ischemia/reperfusion injury. A variety of opportunities to overcome these challenge areas were discussed, i.e. preconditioning for enhanced stress tolerance, nanoparticle rewarming, cyroprotectant screening strategies, and the use of cryoprotectant cocktails including ice binding agents.


Subject(s)
Biological Specimen Banks , Cryopreservation/methods , Cryoprotective Agents/pharmacology , Organ Preservation/methods , Vitrification , Humans , Organ Transplantation
17.
Mol Imaging ; 142015.
Article in English | MEDLINE | ID: mdl-26044881

ABSTRACT

The main scientific issue hindering the development of tissue engineering technologies is the lack of proper vascularization. Among the various approaches developed for boosting vascularization, scaffold design has attracted increasing interest over the last few years. The aim of this article is to illustrate a scaffold design strategy for enhancing vascularization based on sacrificial microfabrication of embedded microchannels. This approach was combined with an innovative poly(ether urethane urea) (PEUtU) porous scaffold to provide an alternative graft substitute material for the treatment of tissue defects. Fluorescent and chemiluminescent imaging combined with computed tomography were used to study the behavior of the scaffold composition within living subjects by analyzing angiogenesis and inflammation processes and observing the variation in x-ray absorption, respectively. For this purpose, an IntegriSense 680 probe was used in vivo for the localization and quantification of integrin αvß3, due to its critical involvement in angiogenesis, and a XenoLight RediJect Inflammation Probe for the study of the decline in inflammation progression during healing. Overall, the collected data suggest the advantages of embedding a synthetic vascular network into a PEUtU porous matrix to enhance in vivo tissue integration, maturation, and regeneration. Moreover, our imaging approach proved to be an efficient and versatile tool for scaffold in vivo testing.


Subject(s)
Diagnostic Imaging/methods , Neovascularization, Physiologic , Tissue Scaffolds/chemistry , Animals , Female , Inflammation/pathology , Mechanical Phenomena , Mice , Porosity , Tomography, X-Ray Computed
18.
Acta Biomater ; 18: 144-54, 2015 May.
Article in English | MEDLINE | ID: mdl-25724444

ABSTRACT

The potential of the 3D cell culture approach for creating in vitro models for drug screening and cellular studies, has led to the development of hydrogels that are able to mimic the in vivo 3D cellular milieu. To this aim, synthetic polymer-based hydrogels, with which it is possible to fine-tune the chemical and biophysical properties of the cell microenvironment, are becoming more and more acclaimed. Of all synthetic materials, poly(amidoamine)s (PAAs) hydrogels are known to have promising properties. In particular, PAAs hydrogels containing the 2,2-bisacrylamidoacetic acid-agmatine monomeric unit are capable of enhancing cellular adhesion by interacting with the RGD-binding αVß3 integrin. The synthesis of a new photocrosslinkable, biomimetic PAA-Jeffamine®-PAA triblock copolymer (PJP) hydrogel is reported in this paper with the aim of improving the optical, biocompatibility and cell-adhesion properties of previously studied PAA hydrogels and providing an inexpensive alternative to the RGD peptide based hydrogels. The physicochemical properties of PJP hydrogels are extensively discussed and the behavior of 2D and 3D cell cultures was analyzed in depth with different cell types. Moreover, cell-laden PJP hydrogels were patterned with perfusable microchannels and seeded with endothelial cells, in order to investigate the possibility of using PJP hydrogels for fabricating cell laden tissue-like micro constructs and microfluidic devices. Overall the data obtained suggest that PJP could ultimately become a useful tool for fabricating improved in vitro models in order to potentially enhance the effectiveness of drug screening and clinical treatments.


Subject(s)
Biomimetic Materials/pharmacology , Hydrogel, Polyethylene Glycol Dimethacrylate/pharmacology , Oligopeptides/pharmacology , Polyamines/pharmacology , Animals , Cell Adhesion/drug effects , Cell Proliferation/drug effects , Elastic Modulus/drug effects , Human Umbilical Vein Endothelial Cells , Humans , Mice , Microfluidics , NIH 3T3 Cells , Optical Phenomena
19.
Biomaterials ; 45: 124-31, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25662502

ABSTRACT

Despite significant progresses were achieved in tissue engineering over the last 20 years, a number of unsolved problems still remain. One of the most relevant issues is the lack of a proper vascularization that is limiting the size of the engineered tissues to smaller than clinically relevant dimensions. Sacrificial molding holds great promise to engineered construct with perfusable vascular architectures, but there is still the need to develop more versatile approaches able to be independent of the nature and dimensions of the construct. In this work we developed a versatile sacrificial molding technique for fabricating bulk, cell-laden and porous scaffolds with embedded vascular fluidic networks. These branched fluidic architectures are created by highly resistant thermoplastic sacrificial templates, made of poly(vinyl alcohol), representing a remarkable progress in manufacturability and scalability. The obtained architecture, when perfused in bioreactor, has shown to prevent the formation of a necrotic core in thick cell-laden constructs and enabled the rapid fabrication of hierarchically branched endothelium. In conclusion we demonstrate a novel strategy towards the engineering of vascularized thick tissues through the integration of the PVA-based microfabrication sacrificial approach and perfusion bioreactors. This approach may be able to scale current engineered tissues to clinically relevant dimensions, opening the way to their widespread clinical applications.


Subject(s)
Bioreactors , Neovascularization, Physiologic , Tissue Engineering/methods , Tissue Scaffolds/chemistry , Animals , Cell Survival , Endothelial Cells/drug effects , Endothelial Cells/metabolism , Fluorescent Antibody Technique , Gels , Mice , Microfluidics , Microtechnology , NIH 3T3 Cells , Optical Imaging , Porosity
20.
Acta Biomater ; 10(3): 1206-15, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24361426

ABSTRACT

Poly(amido-amine) (PAA) hydrogels containing the 2,2-bisacrylamidoacetic acid-4-amminobutyl guanidine monomeric unit have a known ability to enhance cellular adhesion by interacting with the arginin-glycin-aspartic acid (RGD)-binding αVß3 integrin, expressed by a wide number of cell types. Scientific interest in this class of materials has traditionally been hampered by their poor mechanical properties and restricted range of degradation rate. Here we present the design of novel biocompatible, RGD-mimic PAA-based hydrogels with wide and tunable degradation rates as well as improved mechanical and biological properties for biomedical applications. This is achieved by radical polymerization of acrylamide-terminated PAA oligomers in both the presence and absence of 2-hydroxyethylmethacrylate. The degradation rate is found to be precisely tunable by adjusting the PAA oligomer molecular weight and acrylic co-monomer concentration in the starting reaction mixture. Cell adhesion and proliferation tests on Madin-Darby canine kidney epithelial cells show that PAA-based hydrogels have the capacity to promote cell adhesion up to 200% compared to the control. Mechanical tests show higher compressive strength of acrylic chain containing hydrogels compared to traditional PAA hydrogels.


Subject(s)
Hydrogels/pharmacology , Mechanical Phenomena/drug effects , Polyamines/pharmacology , Tissue Engineering/methods , Actins/metabolism , Animals , Cell Adhesion/drug effects , Cell Proliferation/drug effects , Dogs , Hydrogels/chemical synthesis , Hydrogels/chemistry , Madin Darby Canine Kidney Cells , Polyamines/chemical synthesis , Polyamines/chemistry , Polyhydroxyethyl Methacrylate/pharmacology
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