Using 3D Printing Technology to Teach Cartilage Framework Carving for Ear Reconstruction

Objective: The aim of this study was to determine the validity of using a carvable 3D printed rib model in combination with a 3D printed auricular framework to facilitate the teaching, training and planning of auricular reconstruction

3D Bioprinting and the Future of Surgery

Introduction: The disciplines of 3D bioprinting and surgery have witnessed incremental transformations over the last century. 3D bioprinting is a convergence of biology and engineering technologies, mirroring the clinical need to produce viable biological tissue through advancements in printing, regenerative medicine and materials science. To outline the current and future challenges of 3D bioprinting technology in surgery. Methods: A comprehensive literature search was undertaken using the MEDLINE, EMBASE and Google Scholar databases between 2000 and 2019. A narrative synthesis of the resulting literature was produced to discuss 3D bioprinting, current and future challenges, the role in personalized medicine and transplantation surgery and the global 3D bioprinting market. Results: The next 20 years will see the advent of bioprinted implants for surgical use, however the path to clinical incorporation will be fraught with an array of ethical, regulatory and technical challenges of which each must be surmounted. Previous clinical cases where regulatory processes have been bypassed have led to poor outcomes and controversy. Speculated roles of 3D bioprinting in surgery include the production of de novo organs for transplantation and use of autologous cellular material for personalized medicine. The promise of these technologies has sparked an industrial revolution, leading to an exponential growth of the 3D bioprinting market worth billions of dollars. Conclusion: Effective translation requires the input of scientists, engineers, clinicians, and regulatory bodies: there is a need for a collaborative effort to translate this impactful technology into a real-world healthcare setting and potentially transform the future of surgery

Biomimetic Scaffolds Modulate the Posttraumatic Inflammatory Response in Articular Cartilage Contributing to Enhanced Neoformation of Cartilaginous Tissue In Vivo

Focal chondral lesions of the knee are the most frequent type of trauma in younger patients and are associated with a high risk of developing early posttraumatic osteoarthritis. The only current clinical solutions include microfracture, osteochondral grafting, and autologous chondrocyte implantation. Cartilage tissue engineering based on biomimetic scaffolds has become an appealing strategy to repair cartilage defects. Here, a chondrogenic collagen-chondroitin sulfate scaffold is tested in an orthotopic Lapine in vivo model to understand the beneficial effects of the immunomodulatory biomaterial on the full chondral defect. Using a combination of noninvasive imaging techniques, histological and whole transcriptome analysis, the scaffolds are shown to enhance the formation of cartilaginous tissue and suppression of host cartilage degeneration, while also supporting tissue integration and increased tissue regeneration over a 12 weeks recovery period. The results presented suggest that biomimetic materials could be a clinical solution for cartilage tissue repair, due to their ability to modulate the immune environment in favor of regenerative processes and suppression of cartilage degeneration

Nasoseptal chondroprogenitors isolated through fibronectin-adherence confer no biological advantage for cartilage tissue engineering compared to nasoseptal chondrocytes.

The ability to bioprint facial cartilages could revolutionise reconstructive surgery, but identifying the optimum cell source remains one of the great challenges of tissue engineering. Tissue specific stem cells: chondroprogenitors, have been extracted previously using preferential adhesion to fibronectin based on the expression of CD49e: a perceived chondroprogenitor stem cell marker present on <1% of cartilage cells. This study sought to determine whether these fibronectin-adherent chondroprogenitor cells could be exploited for cartilage tissue engineering applications in isolation, or combined with differentiated chondrocytes. Nasoseptal cartilage samples from 20 patients (10 male, 10 female) were digested to liberate cartilage-derived cells (CDCs) from extracellular matrix. Total cell number was counted using the Trypan Blue exclusion assay and added to fibronectin coated plates for 20 min, to determine the proportion of fibronectin-adherent (FAC) and non-adherent cells (NFACs). All populations underwent flow cytometry to detect mesenchymal stem/progenitor cell markers and were cultured in osteogenic, chondrogenic and adipogenic media to determine trilineage differentiation potential. Cell adherence and growth kinetics of the different populations were compared using iCELLigence growth assays. Chondrogenic gene expression was assessed using RT-qPCR for Type 2 collagen, aggrecan and SOX9 genes. Varying proportions of NFAC and FACs were cultured in alginate beads to assess tissue engineering potential. 52.6% of cells were fibronectin adherent in males and 57.7% in females, yet on flow cytometrical analysis, only 0.19% of cells expressed CD49e. Moreover, all cells (CDC, FAC and NFACs) demonstrated an affinity for trilineage differentiation by first passage and the expression of stem/progenitor cell markers increased significantly from digest to first passage (CD29, 44, 49e, 73 and 90, p < 0.0001). No significant differences were seen in adhesion or growth rates. Collagen and aggrecan gene expression was higher in FACs than CDCs (2-fold higher, p = 0.008 and 0.012 respectively), but no differences in chondrogenic potential were seen in any cell mixtures in 3D culture models. The fibronectin adhesion assay does not appear to reliably isolate a chondroprogenitor cell population from nasoseptal cartilage, and these cells confer no advantageous properties for cartilage tissue engineering. Refinement of cell isolation methods and chondroprogenitor markers is warranted for future nasoseptal cartilage tissue engineering efforts. [Abstract copyright: Copyright © 2024 Jovic, Thomson, Jones, Thornton, Doak and Whitaker.

Establishing the Effects of Adipose Derived Stem Cells (ADSCs) on the Tumorigenic Characteristics of Breast Cancer

Introduction: Breast Cancer affects approximately 55,000 women in the UK every year, with the majority (>70%) being oestrogen receptor (ER) positive. Advancements in screening, imaging and adjuvant therapies mean more women are diagnosed earlier and undergo breast-conserving surgery (BCS). There has been a resultant rise in the use of free fat transfer (FFT) to reconstruct the small to medium volume loss, utilising autologous adipose tissue. Contemporary scientific studies demonstrate that co-location of breast cancer and adipose derived stem cells (ADSCs) present in FFT, results in the conference of a malignant advantage via cytokine release and co-located cell-to-cell interaction. As these studies predominantly utilise ADSCs isolated from healthy patients, there is a limit to how these results apply to the clinical patient group of women with breast cancer. This thesis aimed to create, for the first time, a clinically representative model by isolating ADSCs from women with breast cancer undergoing systemic treatment. Thus establishing if patient selection plays a role in the effects imparted by ADSCs upon the functional and phenotypic characteristics associated with the cancer hallmarks. Methods: An optimised ADSC isolation protocol produced a reliable cell population for the study duration. ADSCs harvested from patients with (n=10) and without breast cancer (n=6) were isolated and fully characterised using the Dominici criteria for stem cells. Conditioned media (CM) and non-contact co-culture models were applied to examine the effect that ADSCs isolated from breast cancer patients had on the neoplastic traits of MCF-7 and T47D ER+ breast cancer cell lines when compared with their healthy counterparts. Experiments were designed to measure a range of functional and morphological endpoints, related to the cancer hallmarks. This included proliferation, changes in cellular adhesion and migration, invasion, cellular and nuclei morphology, protein expression and bioenergetics. Results: Successfully isolated ADSCs demonstrated plastic adherence, trilineage differentiation and appropriate cell surface markers as confirmed using flow cytometry. Data showed statistically significant increases (p<0.05) in proliferation and invasion only when MCF-7 cells were treated with media conditioned by ADSCs from healthy patients. Significant increases in migration and invasion, with reduction in adhesion and raised concentrations of cytokines (IL-6, VEG-F and MCP-1) was only seen when MCF-7 cells were co-cultured with ADSCs isolated from healthy patients. There was a lack of effect seen in both CM and co-culture experiments involving ADSCs isolated from cancer patients, a novel finding, as this patient group had not previously been a focus of study. Similar results were seen in the second ER+ cell line (T47D) which was used for experimental validation, with increases in proliferation, invasion, and an increase in abnormal metabolic activity when co-cultured with healthy ADSCs only. Conclusion: Utilising a novel approach to patient selection, it has been possible to show a divergence in the behaviour of ADSCs isolated from patients with breast cancer undergoing systemic treatment, when compared with ADSCs isolated from healthy patients. This study presents a two-part cell-based model which more accurately represents the clinical population undergoing FFT. This study recommends an alternative patient group (women with cancer on systemic treatment) as the primary cell source for research examining ADSC behaviour in the breast cancer micro-environment