Immunogenicity of decellularized porcine liver for bioengineered hepatic tissue.

Liver disease affects millions of patients each year. The field of regenerative medicine promises alternative therapeutic approaches, including the potential to bioengineer replacement hepatic tissue. One approach combines cells with acellular scaffolds derived from animal tissue.

Porcine pancreas extracellular matrix as a platform for endocrine pancreas bioengineering.

Emergent technologies of regenerative medicine have the potential to overcome the limitations of organ transplantation by supplying tissues and organs bioengineered in the laboratory. Pancreas bioengineering requires a scaffold that approximates the biochemical, spatial and vascular relationships of the native extracellular matrix (ECM). We describe the generation of a whole organ, three-dimensional pancreas scaffold using acellular porcine pancreas.

Genetic modification of primate amniotic fluid-derived stem cells produces pancreatic progenitor cells in vitro.

Insulin therapy for type 1 diabetes does not prevent serious long-term complications including vascular disease, neuropathy, retinopathy and renal failure. Stem cells, including amniotic fluid-derived stem (AFS) cells - highly expansive, multipotent and nontumorigenic cells - could serve as an appropriate stem cell source for β-cell differentiation. In the current study we tested whether nonhuman primate (nhp)AFS cells ectopically expressing key pancreatic transcription factors were capable of differentiating into a β-cell-like cell phenotype in vitro.

Decellularization methods of porcine kidneys for whole organ engineering using a high-throughput system.

End-stage renal failure is a devastating disease, with donor organ transplantation as the only functional restorative treatment. The current number of donor organs meets less than one-fifth of demand, so regenerative medicine approaches have been proposed as potential therapeutic alternatives. One such approach for whole large-organ bioengineering is to combine functional renal cells with a decellularized porcine kidney scaffold.

Production and implantation of renal extracellular matrix scaffolds from porcine kidneys as a platform for renal bioengineering investigations.

Background: It is important to identify new sources of transplantable organs because of the critical shortage of donor organs. Tissue engineering holds the potential to address this issue through the implementation of decellularization-recellularization technology.

Objective: To produce and examine acellular renal extracellular matrix (ECM) scaffolds as a platform for kidney bioengineering.

Regenerative medicine as applied to general surgery.

The present review illustrates the state of the art of regenerative medicine (RM) as applied to surgical diseases and demonstrates that this field has the potential to address some of the unmet needs in surgery. RM is a multidisciplinary field whose purpose is to regenerate in vivo or ex vivo human cells, tissues, or organs to restore or establish normal function through exploitation of the potential to regenerate, which is intrinsic to human cells, tissues, and organs. RM uses cells and/or specially designed biomaterials to reach its goals and RM-based therapies are already in use in several clinical trials in most fields of surgery.

A three-dimensional microfluidic approach to scaling up microencapsulation of cells.

Current applications of the microencapsulation technique include the use of encapsulated islet cells to treat Type 1 diabetes, and encapsulated hepatocytes for providing temporary but adequate metabolic support to allow spontaneous liver regeneration, or as a bridge to liver transplantation for patients with chronic liver disease. Also, microcapsules can be used for controlled delivery of therapeutic drugs. The two most widely used devices for microencapsulation are the air-syringe pump droplet generator and the electrostatic bead generator, each of which is fitted with a single needle through which droplets of cells suspended in alginate solution are produced and cross-linked into microbeads.

Design of a bioartificial pancreas(+).

Introduction: In type 1 diabetes, the β-cells that secrete insulin have been destroyed such that daily exogenous insulin administration is required for the control of blood glucose in individuals with the disease. After the development of reliable techniques for the isolation of islets from the human pancreas, islet transplantation has emerged as a therapeutic option, albeit for only a few selected patients largely because there are not enough islets for the millions of patients requiring the treatment, and there is also the need to use immunosuppressive drugs to prevent transplant rejection. In 1980, the concept of islet immunoisolation by microencapsulation was introduced as a technique to overcome these 2 major barriers to islet transplantation.

Whole organ decellularization - a tool for bioscaffold fabrication and organ bioengineering.

The use of synthetic and naturally-derived scaffolds for bioengineering of solid organs has been limited due to a lack of an integrated vascular network. Here, we describe fabrication of a bioscaffold system with intact vascular tree. Animal-donor organs and tissues, ranging in size up-to thirty centimeters, were perfused with decellularization solution to selectively remove the cellular component of the tissue and leave an intact extracellular matrix and vascular network.

Derivation of a novel undifferentiated human foetal phenotype in serum-free cultures with BMP-2.

Skeletal stem and progenitor populations provide a platform for cell-based tissue regeneration strategies. Optimized conditions for ex vivo expansion will be critical and use of serum-free culture may allow enhanced modelling of differentiation potential. Maintenance of human foetal femur-derived cells in a chemically defined medium (CDM) with activin A and fibroblast growth factor-2 generated a unique undifferentiated cell population in comparison to basal cultures, with significantly reduced amino acid depletion, appearance and turnover, reduced alkaline phosphatase (ALP) activity and loss of type I and II collagen expression demonstrated by fluorescence immunocytochemistry.

Biocompatibility and osteogenic potential of human fetal femur-derived cells on surface selective laser sintered scaffolds.

For optimal bone regeneration, scaffolds need to fit anatomically into the requisite bone defects and, ideally, augment cell growth and differentiation. In this study we evaluated novel computationally designed surface selective laser sintering (SSLS) scaffolds for their biocompatibility as templates, in vitro and in vivo, for human fetal femur-derived cell viability, growth and osteogenesis. Fetal femur-derived cells were successfully cultured on SSLS-poly(d,l)-lactic acid (SSLS-PLA) scaffolds expressing alkaline phosphatase activity after 7days.

Adipocyte differentiation induced using nonspecific siRNA controls in cultured human mesenchymal stem cells.

RNA interference (RNAi) is gene silencing induced by double-stranded RNA of 21-23 nucleotides in length, termed small interfering RNA, or siRNA. RNAi-based techniques have been widely applied to elucidate gene function, identify drug targets, and used in trials as a promising adjunct to silence disease-causing genes. However, emerging evidence suggests unexpected changes in expression of untargeted genes as a consequence of an off-target effect by RNAi in mammalian cells.

Characterization and multipotentiality of human fetal femur-derived cells: implications for skeletal tissue regeneration.

To date, the plasticity, multipotentiality, and characteristics of progenitor cells from fetal skeletal tissue remain poorly defined. This study has examined cell populations from human fetal femurs in comparison with adult-derived mesenchymal cell populations. Real-time quantitative polymerase chain reaction demonstrated expression of mesenchymal progenitor cell markers by fetal-derived cells in comparison with unselected adult-derived and immunoselected STRO-1-enriched adult populations.