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Rosenzweig, D.

Publications and source records attributed to Rosenzweig, D..

4 recordsLinked to original sources

3D-Printed Scaffolds for Local Chemotherapeutic Delivery in Resected Spine Metastases

Spinal metastases often occur secondary to breast, lung and prostate cancer and lead to instability, pain and poor quality of life. Standard care for spine metastases includes a multidisciplinary approach with surgery playing a major role in tumor resection, stabilization and decompression. Surgical resection with adjuvant is an effective treatment, yet it is often accompanied by tumor recurrence from residual disease. Furthermore, acrylic cements applied to defect sites provide stability, but they do not promote bone repair and can become destabilized during recurrence events. Developing new tools to stabilize defect sites, promote bone repair and locally deliver therapeutics may circumvent these limitations. We have previously developed mechanically competent 3D printed lactide/mineral scaffolds conducive to bone repair in vivo. We have also developed 3D printed nanoporous scaffolds conducive to both bone repair and chemotherapeutic delivery. Here, we set out to assess doxorubicin and cisplatin uptake and release rates and efficacy of drug delivery in 2D and custom physiological 3D cultures of two human cancer cell lines associated with metastases, MDA-MB-231 (human breast) and C42B (human prostate). Composite scaffolds had a compressive modulus close to trabecular bone, and could sustainably and effectively release doxorubicin and cisplatin as measured against both breast and prostate cell lines in 2D and 3D custom physiological metastases models. As a proof-of-concept, doxorubicin loaded composite scaffolds were implanted into rat caudal vertebrae following MDA-MB-231 xenograft resection. Following 6 weeks of implantation, no adverse events were noted and microCT analysis revealed boney integration of the construct. Taken together, these data indicate that our composite scaffolds may be an appropriate alternate therapy to stabilize bone defects, promote bone repair and effectively inhibit cancer recurrence post-tumor resection. Future work will test composite scaffolds using in vivo bone metastases models.

bioengineering↗

Targeting therapy-induced senescence across multiple breast cancer subtypes in a metastatic bone-like microenvironment

Chemotherapeutic treatment of breast cancer with Doxorubicin (DOX) can induce tumor and stromal cell senescence leading to therapy-resistance. Senescence-associated secretory phenotype (SASP) promotes secretion of pro-inflammatory and tumorigenic factors causing systemic inflammation. Combined, this can result in immune suppression, tumor growth and secondary spread of cancer. Targeting and removing senescent and cancerous cells using a combination of chemotherapeutic and senolytic drugs may reduce systemic inflammation, improve therapeutic efficacy, and prevent metastasis. Exposure of triple-negative breast cancer (MDA-MB-231), hormone-responsive (MCF-7) and HER2+ (MDA-MB-453) cells, and primary spine osteoblasts to DOX showed significant induction of p21-positive senescent cells. DOX and senolytics (RG-7112, o-Vanillin) treatment of co-culture spheroids showed a significant additive effect in reducing tumor sphere viability and growth, indicating reduced metastatic potential. This was correlated with reduced SASP in triple-negative and hormone responsive lines and decreased levels of senescent cells in all subtypes and primary stromal cells, while proliferation was decreased, and apoptosis increased across all breast cancer subtypes. Future chemotherapeutic treatment in breast cancer models may be optimized by adding senolytic drugs to more effectively clear senescent tumor and stromal cells, reducing risk for relapse and metastatic potential, while allowing for tissue regeneration in the bone metastatic environment. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/724653v1_ufig1.gif" ALT="Figure 1"> View larger version (24K): org.highwire.dtl.DTLVardef@c4cb8forg.highwire.dtl.DTLVardef@105219org.highwire.dtl.DTLVardef@17e0517org.highwire.dtl.DTLVardef@802bd2_HPS_FORMAT_FIGEXP M_FIG C_FIG Senolytics selectively eliminate senescent cancer and stromal cells and enhance Doxorubicin efficacy in a 3D bone-like tumor microenvironment model.

cancer biology↗

Uniformity of spheroid-on-chip by surface treatment of PDMS microfluidic platforms

Spheroids have emerged as a more reliable model for drug screening when compared with 2D culture models. Microfluidic based biochips have many advantages over other 3D cell culture models for drug testing on spheroids, including precise control of the cellular microenvironment. The control of the cell adhesion to the surface is one of the most important challenges affecting the size and the geometry of the spheroids which could be controlled by appropriate surface engineering methods. We have studied the modification of the PDMS surface properties treated by applying different concentrations of the two anti-fouling coatings (BSA and Pluronic F-68). The desired treatment of PDMS surface effectively inhibits cell adhesion to the surface and promotes cells self-aggregations to form more uniform and healthy spheroids for a longer period of time. The microscopic observations with qualitative and quantitate data revealed that surface properties drastically affect the number of the spheroids formed on-chip and their geometry. We used human breast cancer cell line (MDA-MB-231-GFP) while the concentration of the chemical coatings and incubation time were adjusted. Proper repellent PDMS surfaces were provided with minimum cell attachment and facilitated spheroid formation when compared with non-treated PDMS. The results demonstrate fundamental and helpful patterns for microfluidic based cell culture applications to improve the quantity and quality of spheroid formation on-chip which are strongly manipulated by surface properties (i.e., morphology, roughness, wettability and etc.)

bioengineering↗

Continuous two-phase in vitro co-culture model of the enthesis

The enthesis is the interfacial tissue between ligament or tendon, and bone, which connects tissues of distinctly different mechanical properties. Although ligament and enthesis injury is commonplace, the development and healing mechanisms of these tissues are yet unclear. Current models for investigating these mechanisms are primarily in vivo animal models as in vitro models have been limited. In this study, an in vitro enthesis model was developed using a modified gel aspiration-ejection (GAE) method. Continuous two-phase aligned dense collagen (ADC) hydrogels with an overlapping interface were fabricated within 2 hours. The mechanical properties of acellular two-phase ADC confirmed the continuous nature of this model, as the mechanical properties showed no significant difference compared to single-phase ADC and maintained comparable structural and mechanical characteristics of immature ligaments and unmineralized bone. Human anterior cruciate ligament (ACL) fibroblasts and human spine vertebral osteoblasts were isolated from donor tissues and were seeded to form the enthesis model. These were cultured for 14 days, at which the viability and proliferation was observed to be 85 {+/-} 7.5% and 230 {+/-} 52%, respectively. Histological and immunofluorescence analyses at day 14 revealed extensive cell-driven matrix remodelling, and the seeded fibroblasts and osteoblasts maintained their phenotype within their compartments of the layered co-culture model. These results demonstrate the rapid fabrication of a two-phase co-culture system that can be utilized as an in vitro model to further understand the degenerative and regenerative mechanisms within the enthesis.

bioengineering↗