Long-term in vivo survival of 3D-bioprinted human lipoaspirate-derived adipose tissue: proteomic signature and cellular content

Abstract

Three-dimensional (3D)-bioprinted lipoaspirate-derived adipose tissue (LAT) is a potential alternative to lipo-injection for correcting soft-tissue defects. This study investigated the long-term in vivo survival of 3D-bioprinted LAT and its proteomic signature and cellular composition. We performed proteomic and multicolour flow cytometric analyses on the lipoaspirate and 3D-bioprinted LAT constructs were transplanted into nude mice, followed by explantation after up to 150 days. LAT contained adipose-tissue-derived stem cells (ASCs), pericytes, endothelial progenitor cells (EPCs) and endothelial cells. Proteomic analysis identified 6,067 proteins, including pericyte markers, adipokines, ASC secretome proteins, proangiogenic proteins and proteins involved in adipocyte differentiation and developmental morphogenic signalling, as well as proteins not previously described in human subcutaneous fat. 3D-bioprinted LAT survived for 150 days in vivo with preservation of the construct shape and size. Furthermore, we identified human blood vessels after 30 and 150 days in vivo , indicating angiogenesis from capillaries. These results showed that LAT has a favourable proteomic signature, contains ASCs, EPCs and blood vessels that survive 3D bioprinting and can potentially facilitate angiogenesis and successful autologous fat grafting in soft-tissue reconstruction.

Clinical Applicability of Visible Light‐Mediated Cross‐linking for Structural Soft Tissue Reconstruction

“…Other studies have attempted to provide reduced fiber diameters and porosity through bioprinting lipoaspirate and nanocellulose composites, however an evaluation and quantification of shape integrity in vitro or in preclinical models was not investigated. [ 26,27 ]…”

“…Other studies have attempted to provide reduced fiber diameters and porosity through bioprinting lipoaspirate and nanocellulose composites, however an evaluation and quantification of shape integrity in vitro or in preclinical models was not investigated. [26,27] Finally, to understand structural maintenance over time, equal volumes of photocrosslinked lipoaspirate (and native nonphotocross-linked controls) were extruded into plastic moulds and the height retention of the sample was measured five minutes after mould removal (Figure 7e,f). There was a significant improvement in height retention of photocross-linked samples (at both 0.05/05 and 0.1/1 mm mm −1 concentrations) compared with native controls (p<0.0001; Figure 7f,g).…”

“…The predominant and most relevant strategies that have previously been used to control the shape and structure of tissue grafts, have been through encapsulating and differentiating mesenchymal stromal cells (e.g., MSCs, or ADSCs) in hydrogel matrices, or forming lipoaspirate composites through addition of supportive polymer matrices. [17,[26][27][28][29][30] The employment of hydrogel support matrices in both instances requires significant manipulation, decellularization or functionalization of tissue components but allows for improved graft structure and offers the potential for further spatial control through application of biofabrication approaches. Nevertheless, the main limitations of these strategies are their restricted scalability, immature adipose tissue products (due to reliance on cellular differentiation), the use of nonclinically approved materials and the need for an invasive surgical implantation (rather than the traditional percutaneous approach as currently used in fat grafting).…”

Adipose‐Derived Stromal Cells Preserve Pancreatic Islet Function in a Transplantable 3D Bioprinted Scaffold

“…[20,28] Another study using the similar 3D scaffold structure and similar number of cell density harvested from fat tissue (containing ASCs, endothelial progenitor cells, and endothelial cells) reported 150 days of scaffold survival in vivo as well as identifications of angiogenesis in nude mouse model. [90] Although in these studies ASCs or MSCs were mixed together in the scaffold, direct co-culture or mixing of islets and ASCs can induce adhesion of ASCs on the islet surface. This can change the morphology of an islet and affect the potency of insulin secretion.…”

Biomaterial and biocompatibility evaluation of tunicate nanocellulose for tissue engineering

“…Although intended for a shorter time perspective, this principle has been previously applied to biodegradable bioinks. Tunicate nanocellulose has previously been used as a scaffold in in vivo studies using nude mice [50][51][52]. In all these studies, TNC was mixed with alginate and crosslinked with Calcium ions prior to implantation.…”