Bone mimetic environments support engineering, propagation, and analysis of therapeutic response of patient-derived cells, ex vivo and in vivo.

Bone metastases are the most common milestone in the lethal progression of prostate cancer and prominent in a substantial portion of renal malignancies. Interactions between cancer and bone host cells have emerged as drivers of both disease progression and therapeutic resistance. To best understand these central host-epithelial cell interactions, biologically relevant preclinical models are required. To achieve this goal, we here established and characterized tissue-engineered bone mimetic environments (BME) capable of supporting the growth of patient-derived xenograft (PDX) cells, ex vivo and in vivo. The BME consisted of a polycaprolactone (PCL) scaffold colonized by human mesenchymal stem cells (hMSCs) differentiated into osteoblasts. PDX-derived cells were isolated from bone metastatic prostate or renal tumors, engineered to express GFP or luciferase and seeded onto the BMEs. BMEs supported the growth and therapy response of PDX-derived cells, ex vivo. Additionally, BMEs survived after in vivo implantation and further sustained the growth of PDX-derived cells, their serial transplant, and their application to study the response to treatment. Taken together, this demonstrates the utility of BMEs in combination with patient-derived cells, both ex vivo and in vivo. STATEMENT OF SIGNIFICANCE: Our tissue-engineered BME supported the growth of patient-derived cells and proved useful to monitor the therapy response, both ex vivo and in vivo. This approach has the potential to enable co-clinical strategies to monitor bone metastatic tumor progression and therapy response, including identification and prioritization of new targets for patient treatment.

Repair of complex ovine segmental mandibulectomy utilizing customized tissue engineered bony flaps.

Craniofacial defects require a treatment approach that provides both robust tissues to withstand the forces of mastication and high geometric fidelity that allows restoration of facial architecture. When the surrounding soft tissue is compromised either through lack of quantity (insufficient soft tissue to enclose a graft) or quality (insufficient vascularity or inducible cells), a vascularized construct is needed for reconstruction. Tissue engineering using customized 3D printed bioreactors enables the generation of mechanically robust, vascularized bony tissues of the desired geometry. While this approach has been shown to be effective when utilized for reconstruction of non-load bearing ovine angular defects and partial segmental defects, the two-stage approach to mandibular reconstruction requires testing in a large, load-bearing defect. In this study, 5 sheep underwent bioreactor implantation and the creation of a load-bearing mandibular defect. Two bioreactor geometries were tested: a larger complex bioreactor with a central groove, and a smaller rectangular bioreactor that were filled with a mix of xenograft and autograft (initial bone volume/total volume BV/TV of 31.8 ± 1.6%). At transfer, the tissues generated within large and small bioreactors were composed of a mix of lamellar and woven bone and had BV/TV of 55.3 ± 2.6% and 59.2 ± 6.3%, respectively. After transfer of the large bioreactors to the mandibular defect, the bioreactor tissues continued to remodel, reaching a final BV/TV of 64.5 ± 6.2%. Despite recalcitrant infections, viable osteoblasts were seen within the transferred tissues to the mandibular site at the end of the study, suggesting that a vascularized customized bony flap is a potentially effective reconstructive strategy when combined with an optimal stabilization strategy and local antibiotic delivery prior to development of a deep-seated infection.

Bilayered, peptide-biofunctionalized hydrogels for in vivo osteochondral tissue repair.

Osteochondral defects present a unique clinical challenge due to their combination of phenotypically distinct cartilage and bone, which require specific, stratified biochemical cues for tissue regeneration. Furthermore, the articular cartilage exhibits significantly worse regeneration than bone due to its largely acellular and avascular nature, prompting significant demand for regenerative therapies. To address these clinical challenges, we have developed a bilayered, modular hydrogel system that enables the click functionalization of cartilage- and bone-specific biochemical cues to each layer. In this system, the crosslinker poly(glycolic acid)-poly(ethylene glycol)-poly(glycolic acid)-di(but-2-yne-1,4-dithiol) (PdBT) was click conjugated with either a cartilage- or bone-specific peptide sequence of interest, and then mixed with a suspension of thermoresponsive polymer and mesenchymal stem cells (MSCs) to generate tissue-specific, cell-encapsulated hydrogel layers targeting the cartilage or bone. We implanted bilayered hydrogels in rabbit femoral condyle defects and investigated the effects of tissue-specific peptide presentation and cell encapsulation on osteochondral tissue repair. After 12 weeks implantation, hydrogels with a chondrogenic peptide sequence produced higher histological measures of overall defect filling, cartilage surface regularity, glycosaminoglycan (GAG)/cell content of neocartilage and adjacent cartilage, and bone filling and bonding compared to non-chondrogenic hydrogels. Furthermore, MSC encapsulation promoted greater histological measures of overall defect filling, cartilage thickness, GAG/cell content of neocartilage, and bone filling. Our results establish the utility of this click functionalized hydrogel system for in vivo repair of the osteochondral unit. STATEMENT OF SIGNIFICANCE: Osteochondral repair requires mimicry of both cartilage- and bone-specific biochemical cues, which are highly distinct. While traditional constructs for osteochondral repair have mimicked gross compositional differences between the cartilage and bone in mineral content, mechanical properties, proteins, or cell types, few constructs have recapitulated the specific biochemical cues responsible for the differential development of cartilage and bone. In this study, click biofunctionalized, bilayered hydrogels produced stratified presentation of developmentally inspired peptide sequences for chondrogenesis and osteogenesis. This work represents, to the authors' knowledge, the first application of bioconjugation chemistry for the simultaneous repair of bone and cartilage tissue. The conjugation of tissue-specific peptide sequences successfully promoted development of both cartilage and bone tissues in vivo.

Hydrophobic Domain Structure of Linear-Dendritic Poly(ethylene glycol) Lipids Affects RNA Delivery of Lipid Nanoparticles.

In this work, a series of linear-dendritic poly(ethylene glycol) (PEG) lipids (PEG-GnCm) were synthesized through a strategy using sequential aza- and sulfa-Michael addition reactions. The effect of modulating the hydrophobic domain of linear-dendritic PEG lipids was systematically investigated for in vitro and in vivo small RNA delivery as the surface-stabilizing component of 5A2-SC8 dendrimer lipid-based nanoparticles (DLNPs). The lipid alkyl lengths (C8, C12, and C16) and dendrimer generations (G1, G2, and G3) were altered to create PEG-GnCm with different physical properties and anchoring potential. The tail chemical structure of PEG-GnCm did not affect the formulation of 5A2-SC8 DLNPs, including the nanoparticle size, RNA encapsulation, and stability. However, the tail chemical structure did dramatically affect the RNA delivery efficacy of the formed 5A2-SC8 DLNPs with different PEG-GnCm. First-generation PEG lipids (PEG-G1C8, PEG-G1C12, and PEG-G1C16) and a second-generation PEG lipid (PEG-G2C8) formed 5A2-SC8 DLNPs that could deliver siRNAs effectively in vitro and in vivo. 5A2-SC8 DLNPs formulated with second-generation PEG lipids (PEG-G2C12 and PEG-G2C16) and all three third-generation PEG lipids (PEG-G3C8, PEG-G3C12, and PEG-G3C16) lost the ability to deliver siRNA effectively in vitro and in vivo. Overall, we determined that the hydrophobic domain chemical structure of linear-dendritic poly(ethylene glycol) lipids affected the RNA delivery of DLNPs by impacting the escape of 5A2-SC8 DLNPs from endosomes at early cell incubation times, thereby indicating how PEG lipid anchoring and chemical structure can modulate in vitro and in vivo siRNA delivery efficacies.

Modeling the Tumor Microenvironment and Pathogenic Signaling in Bone Sarcoma.

Investigations of cancer biology and screening of potential therapeutics for efficacy and safety begin in the preclinical laboratory setting. A staple of most basic research in cancer involves the use of tissue culture plates, on which immortalized cell lines are grown in monolayers. However, this practice has been in use for over six decades and does not account for vital elements of the tumor microenvironment that are thought to aid in initiation, propagation, and ultimately, metastasis of cancer. Furthermore, information gleaned from these techniques does not always translate to animal models or, more crucially, clinical trials in cancer patients. Osteosarcoma (OS) and Ewing sarcoma (ES) are the most common primary tumors of bone, but outcomes for patients with metastatic or recurrent disease have stagnated in recent decades. The unique elements of the bone tumor microenvironment have been shown to play critical roles in the pathogenesis of these tumors and thus should be incorporated in the preclinical models of these diseases. In recent years, the field of tissue engineering has leveraged techniques used in designing scaffolds for regenerative medicine to engineer preclinical tumor models that incorporate spatiotemporal control of physical and biological elements. We herein review the clinical aspects of OS and ES, critical elements present in the sarcoma microenvironment, and engineering approaches to model the bone tumor microenvironment. Impact statement The current paradigm of cancer biology investigation and therapeutic testing relies heavily on monolayer, monoculture methods developed over half a century ago. However, these methods often lack essential hallmarks of the cancer microenvironment that contribute to tumor pathogenesis. Tissue engineers incorporate scaffolds, mechanical forces, cells, and bioactive signals into biological environments to drive cell phenotype. Investigators of bone sarcomas, aggressive tumors that often rob patients of decades of life, have begun to use tissue engineering techniques to devise in vitro models for these diseases. Their efforts highlight how critical elements of the cancer microenvironment directly affect tumor signaling and pathogenesis.

Lesiones por virus de papiloma humano de la vía aerodigestiva superior, incidencia de subtipos / Human papilloma virus related lesions of the upper aerodigestive tract, incidence of subtypes / Lesões por vírus do papiloma humano do trato aerodigestivo superior - Incidência de subtipos

Antecedentes: el cáncer de la vía aerodigestiva superior (CVADS), al que con frecuencia se lo engloba como “cáncer de cabeza y cuello”, tiene una incidencia aproximada de 30 nuevos casos cada 100.000 habitantes por año, habiendo presentado un aumento significativo en la última década. Los principales factores de riesgo para el CVADS siguen siendo la exposición al tabaco y el alcohol, pero el virus del papiloma humano (VPH) se ha encontrado asociado en la etiología del 20 al 25% de los CVADS, principalmente los ubicados en la región de la orofaringe. El virus tiene dos oncoproteínas, E6 y E7. E6 tiene la propiedad de unirse a la proteína celular p53, que regula la transcripción de la p21 e inhibe las quinasas ciclindependientes, las cuales son esenciales para la progresión del ciclo celular a la fase S, haciendo que la célula se replique descontroladamente...

Background: cancer of the upper aerodigestive tract (cuadt) that often encompasses it as “cancer of the head and neck, has an incidence of 30 new cases per 100,000 population per year, having presented a significant increase in the last decade. The main risk factors for CUADT remain exposure to tabaco and alcohol, but the human papillomavirus (HPV) has been found associated in the etiology of 20 to 25% of CUADT, mainly those located in the region oropharynx. The virus has two oncoproteins E6 and E7. E6 has the property of binding to cellular p53 protein that regulates transcription of p21, which inhibits cyclin dependent-kinases which are essential for cell cycle progression to S phase causing the cell to replicate uncontrollably...

Antecedentes: o câncer do trato aerodigestivo superior, que é frequentemente englobado no “câncer de cabeça e pescoço”, tem uma incidência aproximada de 30 casos novos cada 100.000 habitantes por ano, com um incremento significativo na última dé- cada. Os principais fatores de risco para o câncer de cabeça e de pescoço continuam sendo a exposição ao tabaco e ao álcool, mas o vírus do papiloma humano (VPH) é associado na etiologia de 20% até 25% dos casos de câncer do trato aerodigestivo superior, principalmente nos localizados na região da orofaringe. O vírus contém duas oncoproteínas E6 e E7. A E6 tem a propriedade de se unir à proteí- na celular p53, a qual regula a transcrição da p21, a qual inibe as quinases dependentes de ciclina que são essenciais para a progressão do ciclo celular à fase S, fazendo com que a célula se replique descontroladamente...