Additive manufacturing, or 3D printing, has reimagined the way manufacturing is accomplished and brought in a new concept for prototype generation. Typical, polymer-melt printing, however is unsuitable for generation of tissue engineering products such as stem-cell seeded scaffolds or other bioactive materials. For this, 3D printing can be accomplished by printing a cold solution comprised of a thermosentive polymer dissolved in cell-growth media or other suitable aqueous solution onto a gently warmed platform (~37 °C). There are, however, drawbacks to this technique in that the thermogelation of polymers does not provide for high mechanical strength. To address this need, PolySciTech has launched PolyVivo AI145 (https://akinainc.com/polyscitech/products/polyvivo/?highlight=AI145#h). This is a thermogelling PLA-PEG-PLA with diacrylate endcaps that gels at 37 °C and allows for the gelled structures to be reinforced by photo-initiation of the acrylates to form a biodegradable crosslinked structure. Such a system could allow for 3D printing of cell-seeded thermogels with suitable mechanical requirements to allow for printing a structure with height and geometry not possible so far with conventional thermogelation 3D printing.
A similar type process was applied by researchers in Tornio, Italy for generating a sol-gel printed substrate. This research holds promise for the development of reinforced tissue scaffolds for cellular growth or tissue repair as well as other engineered materials. Read more: Chiappone, Annalisa, Erika Fantino, Ignazio Roppolo, Massimo Lorusso, Diego Manfredi, Paolo Fino, Candido Fabrizio Pirri, and Flaviana Calignano. "3D Printed PEG-Based Hybrid Nanocomposites Obtained by Sol–Gel Technique." ACS applied materials & interfaces 8, no. 8 (2016): 5627-5633. http://pubs.acs.org/doi/abs/10.1021/acsami.5b12578
“In this work, three-dimensional (3D) structured hybrid materials were fabricated combining 3D printing technology with in situ generation of inorganic nanoparticles by sol–gel technique. Those materials, consisting of silica nanodomains covalently interconnected with organic polymers, were 3D printed in complex multilayered architectures, incorporating liquid silica precursors into a photocurable oligomer in the presence of suitable photoinitiators and exposing them to a digital light system. A post sol–gel treatment in acidic vapors allowed the in situ generation of the inorganic phase in a dedicated step. This method allows to build hybrid structures operating with a full liquid formulation without meeting the drawbacks of incorporating inorganic powders into 3D printable formulations. The influence of the generated silica nanoparticle on the printed objects was deeply investigated at macro- and nanoscale; the resulting light hybrid structures show improved mechanical properties and, thus, have a huge potential for applications in a variety of advanced technologies. Keywords: 3D printing; digital light processing (DLP); hybrid nanocomposite; mechanical properties; sol−gel”