^{A Paradigm for the Evaluation of Tissue-Engineering Biomaterials and Templates}

Abstract

Procedures for the evaluation of tissue-engineering processes, including those used for the testing of the relevant biomaterials, have not been developed in a logical manner. This perspectives paper discusses the limitations of testing regimes and recommends a very different approach. The main emphasis is on the existing methods for assessing the biological safety of these biomaterials, which, it is suggested, are irrelevant for evaluating materials that are intended to facilitate the generation of new tissue. An algorithm is proposed that sets out the pathway from materials design and characterization through to the production of a file that sets out full biocompatibility, functionality, and tissue incorporation data that are suitable for regulatory consideration for first-in-man experiences. Central to this algorithm is the choice of animal models and the real-time monitoring of the implanted construct performance.

Amorphous polyphosphate, a smart bioinspired nano-/bio-material for bone and cartilage regeneration: towards a new paradigm in tissue engineering

“…-is physiologically suitable -is amorphous -has metabolic energy required for the maintenance of the extracellular supramolecular architecture -provides with monomeric phosphate units as essential building groups for bone (hydroxyapatite) formation -can be coated around (bio-inert) scaffolds -allows the integration of biologically active components, like peptides or drugs -is not only a scaffold supporting cellular growth but promotes growth and differentiation of cells. By this, polyP is en route to follow the formulated forward-looking concept 240,241 -is not only a solid, macroscopic polymer, designed ''with robustness in mind'' and ''manufactured by conventional engineering routes'' but is provided with the potential to selfassemble at the nanoscale in a dynamic process during which new biological functionalities are gained.…”

Biological responses to physicochemical properties of biomaterial surface

“…468 Considering the other potential key biochemical signals which might be involved in biological responses to a material and can affect the evaluation criteria of material safety in the body is important. 12 Traditionally biocompatibility was investigated by considering the wound healing processes that occur after biomaterial implantation. The in vivo evaluation of biological responses to biomaterials involves implanting biomaterials in the targeted tissues at certain time points and then studying the histological changes in the implanted tissue and its surroundings.…”

“…[495][496][497][498] Although these computational models might strongly help in evaluating and predicting biomaterial-host complex interactions and decrease the number of unnecessary animal studies, without doing any animal studies we cannot make well-founded decisions regarding the safety of biomaterials and directly implant them in the human body with confidence. 12 Considering more quantitative and statistical analyses can help us to make conclusions that are more convincing. Due to the immense development of new biomaterials for tissue engineering applications, researchers design more and more tissue-engineered templates with different chemistry.…”

Transformation of Amorphous Polyphosphate Nanoparticles into Coacervate Complexes: An Approach for the Encapsulation of Mesenchymal Stem Cells

“…Often, implant materials that show maximal inertness are chosen. Their host response(s) are controlled only by biomechanical factors . The (close to) ideal implant material should not only meet the mechanical and physical functionalities of the surrounding tissue but also function actively to deliver regeneratively acting material.…”