title: The use of collagen-based scaffolds to simulate prostate cancer bone metastases with potential for evaluating delivery of nanoparticulate gene therapeutics.
abstract: Prostate cancer bone metastases are a leading cause of cancer-related death in men with current treatments offering only marginally improved rates of survival. Advances in the understanding of the genetic basis of prostate cancer provide the opportunity to develop gene-based medicines capable of treating metastatic disease. The aim of this work was to establish a 3D cell culture model of prostate cancer bone metastasis using collagen-based scaffolds, to characterise this model, and to assess the potential of the model to evaluate delivery of gene therapeutics designed to target bone metastases. Two prostate cancer cell lines (PC3 and LNCaP) were cultured in 2D standard culture and compared to 3D cell growth on three different collagen-based scaffolds (collagen and composites of collagen containing either glycosaminoglycan or nanohydroxyapatite). The 3D model was characterised for cell proliferation, viability and for matrix metalloproteinase (MMP) enzyme and Prostate Specific Antigen (PSA) secretion. Chemosensitivity to docetaxel treatment was assessed in 2D in comparison to 3D. Nanoparticles (NPs) containing siRNA formulated using a modified cyclodextrin were delivered to the cells on the scaffolds and gene silencing was quantified. Both prostate cancer cell lines actively infiltrated and proliferated on the scaffolds. Cell culture in 3D resulted in reduced levels of MMP1 and MMP9 secretion in PC3 cells. In contrast, LNCaP cells grown in 3D secreted elevated levels of PSA, particularly on the scaffold composed of collagen and glycosaminoglycans. Both cell lines grown in 3D displayed increased resistance to docetaxel treatment. The cyclodextrin.siRNA nanoparticles achieved cellular uptake and knocked down the endogenous GAPDH gene in the 3D model. In conclusion, development of a novel 3D cell culture model of prostate cancer bone metastasis has been initiated resulting, for the first time, in the successful delivery of gene therapeutics in a 3D in vitro model. Further enhancement of this model will help elucidate the pathogenesis of prostate cancer and also accelerate the design of effective therapies which can penetrate into the bone microenvironment for prostate cancer therapy.
authors.affiliation: Pharmacodelivery Group, School of Pharmacy, University College Cork, Ireland.
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Fitzgerald
authors.affiliation: Pharmacodelivery Group, School of Pharmacy, University College Cork, Ireland.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Guo
authors.affiliation: Tissue Engineering Research Group, Anatomy Department, Royal College of Surgeons in Ireland, Dublin, Ireland; Trinity Centre for Bioengineering, Trinity College, Dublin, Ireland; Advanced Materials and Bioengineering Research (AMBER) Centre, RCSI & TCD, Ireland.
authors.forename: Erica G
authors.initials: EG
authors.lastname: Tierney
authors.affiliation: Tissue Engineering Research Group, Anatomy Department, Royal College of Surgeons in Ireland, Dublin, Ireland; Trinity Centre for Bioengineering, Trinity College, Dublin, Ireland; Advanced Materials and Bioengineering Research (AMBER) Centre, RCSI & TCD, Ireland.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Curtin
authors.affiliation: Pharmacodelivery Group, School of Pharmacy, University College Cork, Ireland.
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Malhotra
authors.affiliation: Centre for Synthesis and Chemical Biology, University College Dublin, Ireland.
authors.forename: Raphael
authors.initials: R
authors.lastname: Darcy
authors.affiliation: Tissue Engineering Research Group, Anatomy Department, Royal College of Surgeons in Ireland, Dublin, Ireland; Trinity Centre for Bioengineering, Trinity College, Dublin, Ireland; Advanced Materials and Bioengineering Research (AMBER) Centre, RCSI & TCD, Ireland.
authors.forename: Fergal J
authors.initials: FJ
authors.lastname: O'Brien
authors.affiliation: Pharmacodelivery Group, School of Pharmacy, University College Cork, Ireland. Electronic address: caitriona.odriscoll@ucc.ie.
authors.forename: Caitriona M
authors.initials: CM
authors.lastname: O'Driscoll
mesh_terms: D061249:Batch Cell Culture Techniques / Q000295:instrumentation*; D001859:Bone Neoplasms / Q000235:genetics* / Q000556:secondary* / Q000628:therapy; D045744:Cell Line, Tumor; D024042:Collagen Type I / Q000737:chemistry*; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D015316:Genetic Therapy / Q000295:instrumentation; D006801:Humans; D008297:Male; D053769:Nanocapsules / Q000008:administration & dosage; D066330:Printing, Three-Dimensional; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D034741:RNA, Small Interfering / Q000008:administration & dosage / Q000235:genetics; D023822:Tissue Engineering / Q000295:instrumentation; D054457:Tissue Scaffolds
chemical_list: D024042:Collagen Type I; D053769:Nanocapsules; D034741:RNA, Small Interfering
keywords: 3D bone cancer in vitro model; Bone microenvironment; Collagen scaffolds; Gene therapy; Prostate cancer metastasis; siRNA delivery