Novel Sheep Model to Assess Critical-Sized Bone Regeneration with Periosteum for In Vivo Bioreactors

Considerable research is being undertaken to develop novel biomaterials-based approaches for surgical reconstruction of bone defects. This extends to three-dimensional (3D) printed materials that provide stable, structural, and functional support in vivo. However, few preclinical models can simulate in vivo human biological conditions for clinically relevant testing. In this study we describe a novel ovine model that allows evaluation of in vivo osteogenesis via contact with bone and/or periosteum interfaced with printed polymer bioreactors loaded with biomaterial bone substitutes. The infraspinous scapular region of 14 Dorset cross sheep was exposed. Vascularized periosteum was elevated either attached to the infraspinatus muscle or separately. In both cases, the periosteum was supplied by the periosteal branch of the circumflex scapular vessels. In eight sheep, a 3D printed 4-chambered polyetheretherketone bioreactor was wrapped circumferentially in vascularized periosteum. In 6 sheep, 12 double-sided 3D printed 2-chambered polyetherketone bioreactors were secured to the underlying bone allowing direct contact with the bone on one side and periosteum on the other. Our model enabled simultaneous testing of up to 24 (12 double-sided) 10 × 10 × 5 mm bioreactors per scapula in the flat contact approach or a single 40 × 10 mm four-chambered bioreactor per scapula using the periosteal wrap. De novo bone growth was evaluated using histological and radiological analysis. Of importance, the experimental model was well tolerated by the animals and provides a versatile approach for comparing the osteogenic potential of cambium on the bone surface and elevated with periosteum. Furthermore, the periosteal flaps were sufficiently large for encasing bioreactors containing biomaterial bone substitutes for applications such as segmental mandibular reconstruction.

Electro-compacted collagen for corneal epithelial tissue engineering

Bioengineered corneal substitutes offer a solution to the shortage of donor corneal tissue worldwide. As one of the major structural components of the cornea, collagen has shown great potential for tissue-engineered cornea substitutes. Herein, free-standing collagen membranes fabricated using electro-compaction were assessed in corneal bioengineering application by comparing them with nonelectro-compacted collagen (NECC). The well-organized and biomimetic fibril structure resulted in a significant improvement in mechanical properties. A 10-fold increase in tensile and compressive modulus was recorded when compared with NECC membranes. In addition to comparable transparency in the visible light range, the glucose permeability of the electro-compacted collagen (ECC) membrane is higher than that of the native human cornea. Human corneal epithelial cells adhere and proliferate well on the ECC membrane, with a large cell contact area observed. The as-described ECC has appropriate structural, topographic, mechanical, optical, glucose permeable, and cell support properties to provide a platform for a bioengineered cornea; including the outer corneal epithelium and potentially deeper corneal tissues.

Long-Term Biochemical Control of a Prospective Cohort of Prostate Cancer Patients Treated With Interstitial Brachytherapy Versus Radical Prostatectomy

AIMS

To report long-term oncological outcomes of men treated prospectively as part of the American College of Surgeons Oncology Group phase III Surgical Prostatectomy Versus Interstitial Radiation Intervention Trial (SPIRIT) at our institution.

MATERIALS AND METHODS

In 2003-2004, patients eligible for SPRIT attended a multidisciplinary educational session, following which they could choose radical prostatectomy, low dose rate brachytherapy (LDR-BT) or randomisation to SPIRIT. Biochemical failure was determined by the accepted definitions of a prostate-specific antigen (PSA) level ≥0.2 ng/ml after radical prostatectomy and the Phoenix definition of PSA ≥2 ng/ml above the nadir after LDR-BT. A sensitivity analysis, using a PSA >0.5 ng/ml to define biochemical failure after LDR-BT and a threshold PSA ≥0.2 ng/ml, was carried out to test the robustness of the results. To account for the competing risk of death, Gray's test was used to test the equality of the cumulative incidence function of biochemical failure between treatment groups. The Kaplan-Meier method was used to estimate overall survival and prostate cancer-specific survival. A P-value ≤0.05 was considered statistically significant.

RESULTS

Of 156 patients, 100 received LDR-BT (15 after randomisation) and 56 underwent radical prostatectomy (15 after randomisation). The median follow-up was 12.6 and 14.7 years for LDR-BT and radical prostatectomy, respectively. The median age was 60 years; the median pre-treatment PSA was 5.5 (interquartile range 4.3-7.1). No significant differences in patient characteristics were found between groups. Two patients received adjuvant radiotherapy after radical prostatectomy. The cumulative incidence function of biochemical failure was 0%, 1.1% and 2.4% at 5, 10 and 15 years, respectively, in the LDR-BT arm versus 8.5%, 15.8% and 15.8% in the radical prostatectomy arm (P < 0.001). These results were consistent when varying the definition of biochemical failure defined as PSA ≥0.5 ng/ml (P = 0.01). At 15 years, overall survival was higher in patients treated with radical prostatectomy compared with those treated with LDR-BT; however, no statistical difference was found in prostate cancer-specific survival.

CONCLUSION

In low-risk prostate cancer patients, LDR-BT offers excellent long-term oncological outcomes comparable with radical prostatectomy, in addition to the previously reported advantage for LDR-BT in urinary and sexual quality of life domains and patient satisfaction.

OA32 Minimally invasive, ultrasound-guided tissue biopsies of synovial tissue in children with Juvenile Idiopathic Arthritis for research: a feasibility study

Introduction/Background

When investigating disease mechanisms, site-specific differences in immune cell phenotype and function have highlighted the need to analyse cellular and molecular mechanisms at the tissue site directly. In adults, the ability to obtain synovial tissue biopsies using ultrasound-guided techniques, combined with advanced tissue analytics, has revolutionised our understanding of the cellular ecosystem that operates within the joint and how it contributes to disease. However, a similar approach in paediatric disease is lacking.

Description/Method

Aims: 1) To describe the protocol for undertaking minimally invasive ultrasound-guided synovial tissue biopsies in children and young people with arthritis, for the purpose of research, alongside routine clinical care. 2) To investigate whether high-quality synovial tissue can be obtained that is suitable for downstream applications including single cell profiling technologies, histology and digital spatial profiling.

Treatment-naïve children with a diagnosis of Juvenile Idiopathic Arthritis, who were being referred for a corticosteroid joint injection were recruited from two large UK Paediatric Rheumatology centres. We established a workflow pipeline for performing synovial tissue biopsies in child and young people with arthritis, using standardised procedures for biopsy and sample processing. Procedures were performed by experienced paediatric interventional radiologists with experience of joint biopsy for diagnostic purposes. Following a general anaesthetic, required as part of routine clinical care and the establishment of sterility, synovial fluid was aspirated. Needle-biopsies were undertaken from the same needle insertion site and subsequently corticosteroid was injected into the joint. Thickened synovium was graded via ultrasonography. Participating families completed questionnaires prior to and following synovial biopsy.

Discussion/Results

11 participants were recruited to the study over a nine month period, with a median age of 7 years (range 1-16 years); 91% were female. Samples obtained included core synovial biopsies, paired synovial fluid and peripheral blood. Synovial tissue fragments were processed for histology by formalin fixation and cryopreserved for downstream applications, including RNA sequencing and cell culture. Quality control indices included histological analysis to ensure the biopsied material was characteristically synovium and to grade the severity of inflammation. No significant complications were reported; however, one child had a mild haemarthrosis controlled with cold saline wash out and cold compresses.

Key learning points/Conclusion

Obtaining biopsies of synovial tissue in children with Juvenile Idiopathic Arthritis for the purpose of research, alongside clinical care is feasible. Analysis of tissue direct from the site of inflammation with single-cell RNA sequencing in children is achievable.

Wet-Spun Trojan Horse Cell Constructs for Engineering Muscle

Engineering of 3D regenerative skeletal muscle tissue constructs (skMTCs) using hydrogels containing muscle precursor cells (MPCs) is of potential benefit for repairing Volumetric Muscle Loss (VML) arising from trauma (e.g., road/industrial accident, war injury) or for restoration of functional muscle mass in disease (e.g., Muscular Dystrophy, muscle atrophy). Additive Biofabrication (AdBiofab) technologies make possible fabrication of 3D regenerative skMTCs that can be tailored to specific delivery requirements of VML or functional muscle restoration. Whilst 3D printing is useful for printing constructs of many tissue types, the necessity of a balanced compromise between cell type, required construct size and material/fabrication process cyto-compatibility can make the choice of 3D printing a secondary alternative to other biofabrication methods such as wet-spinning. Alternatively, wet-spinning is more amenable to formation of fibers rather than (small) layered 3D-Printed constructs. This study describes the fabrication of biosynthetic alginate fibers containing MPCs and their use for delivery of dystrophin-expressing cells to dystrophic muscle in the mdx mouse model of Duchenne Muscular Dystrophy (DMD) compared to poly(DL-lactic-co-glycolic acid) copolymer (PLA:PLGA) topically-seeded with myoblasts. In addition, this study introduces a novel method by which to create 3D layered wet-spun alginate skMTCs for bulk mass delivery of MPCs to VML lesions. As such, this work introduces the concept of "Trojan Horse" Fiber MTCs (TH-fMTCs) and 3d Mesh-MTCs (TH-mMTCs) for delivery of regenerative MPCs to diseased and damaged muscle, respectively.

Report of the International Stem Cell Banking Initiative Workshop Activity: Current Hurdles and Progress in Seed-Stock Banking of Human Pluripotent Stem Cells

This article summarizes the recent activity of the International Stem Cell Banking Initiative (ISCBI) held at the California Institute for Regenerative Medicine (CIRM) in California (June 26, 2016) and the Korean National Institutes for Health in Korea (October 19-20, 2016). Through the workshops, ISCBI is endeavoring to support a new paradigm for human medicine using pluripotent stem cells (hPSC) for cell therapies. Priority considerations for ISCBI include ensuring the safety and efficacy of a final cell therapy product and quality assured source materials, such as stem cells and primary donor cells. To these ends, ISCBI aims to promote global harmonization on quality and safety control of stem cells for research and the development of starting materials for cell therapies, with regular workshops involving hPSC banking centers, biologists, and regulatory bodies. Here, we provide a brief overview of two such recent activities, with summaries of key issues raised. Stem Cells Translational Medicine 2017;6:1956-1962.

Urodynamic function during sleep-like brain states in urethane anesthetized rats

The aim was to investigate urodynamic parameters and functional excitability of the periaqueductal gray matter (PAG) during changes in sleep-like brain states in urethane anesthetized rats. Simultaneous recordings of detrusor pressure, external urethral sphincter (EUS) electromyogram (EMG), cortical electroencephalogram (EEG), and single-unit activity in the PAG were made during repeated voiding induced by continuous infusion of saline into the bladder. The EEG cycled between synchronized, high-amplitude slow wave activity (SWA) and desynchronized low-amplitude fast activity similar to slow wave and 'activated' sleep-like brain states. During (SWA, 0.5-1.5 Hz synchronized oscillation of the EEG waveform) voiding became more irregular than in the 'activated' brain state (2-5 Hz low-amplitude desynchronized EEG waveform) and detrusor void pressure threshold, void volume threshold and the duration of bursting activity in the external urethral sphincter EMG were raised. The spontaneous firing rate of 23/52 neurons recorded within the caudal PAG and adjacent tegmentum was linked to the EEG state, with the majority of responsive cells (92%) firing more slowly during SWA. Almost a quarter of the cells recorded (12/52) showed phasic changes in firing rate that were linked to the occurrence of voids. Inhibition (n=6), excitation (n=4) or excitation/inhibition (n=2) was seen. The spontaneous firing rate of 83% of the micturition-responsive cells was sensitive to changes in EEG state. In nine of the 12 responsive cells (75%) the responses were reduced during SWA. We propose that during different sleep-like brain states changes in urodynamic properties occur which may be linked to changing excitability of the micturition circuitry in the periaqueductal gray.

Effects of UV irradiation in a continuous turbulent flow UV reactor on microbiological and sensory characteristics of cow's milk

The dairy industry under current pasteurization conditions (15 s at 72°C) and sanitary standards achieves a safe product with excellent quality. In an ever-competitive market there is still a need to improve product quality and extend shelf life of dairy products to increase competitiveness and open up new markets. In an attempt to test the effect of UV irradiation on microbiota of fluid milk, a continuous flow UV system at 254 nm was used to treat 3.5 and 2% fat milk at two UV doses (880 and 1,760 J liter(-1)). Milk was obtained from three processors, and two lots from each processor were assessed. To assess the impact on the most descriptive native microbiota in pasteurized milk after UV illumination, the product was held at two storage temperatures (4 and 7°C) and tested weekly for 5 weeks for aerobic plate counts (psychrotrophic and mesophilic bacteria), laboratory pasteurization counts, aerobic sporeformers, coliform organisms, and titratable acidity. Microbial counts for all tested microorganisms were lower in UV-treated milk when compared with control throughout storage at 4 and 7°C in both 3.5 and 2% fat milk. Sensory analysis indicated that there is a sensory defect associated with UV treatment at the wavelength used.

TMEM106B regulates progranulin levels and the penetrance of FTLD in GRN mutation carriers

OBJECTIVES

To determine whether TMEM106B single nucleotide polymorphisms (SNPs) are associated with frontotemporal lobar degeneration (FTLD) in patients with and without mutations in progranulin (GRN) and to determine whether TMEM106B modulates GRN expression.

METHODS

We performed a case-control study of 3 SNPs in TMEM106B in 482 patients with clinical and 80 patients with pathologic FTLD-TAR DNA-binding protein 43 without GRN mutations, 78 patients with FTLD with GRN mutations, and 822 controls. Association analysis of TMEM106B with GRN plasma levels was performed in 1,013 controls and TMEM106B and GRN mRNA expression levels were correlated in peripheral blood samples from 33 patients with FTLD and 150 controls.

RESULTS

In our complete FTLD patient cohort, nominal significance was identified for 2 TMEM106B SNPs (top SNP rs1990622, p(allelic) = 0.036). However, the most significant association with risk of FTLD was observed in the subgroup of GRN mutation carriers compared to controls (corrected p(allelic) = 0.0009), where there was a highly significant decrease in the frequency of homozygote carriers of the minor alleles of all TMEM106B SNPs (top SNP rs1990622, CC genotype frequency 2.6% vs 19.1%, corrected p(recessive) = 0.009). We further identified a significant association of TMEM106B SNPs with plasma GRN levels in controls (top SNP rs1990622, corrected p = 0.002) and in peripheral blood samples a highly significant correlation was observed between TMEM106B and GRN mRNA expression in patients with FTLD (r = -0.63, p = 7.7 × 10(-5)) and controls (r = -0.49, p = 2.2 × 10(-10)).

CONCLUSIONS

In our study, TMEM106B SNPs significantly reduced the disease penetrance in patients with GRN mutations, potentially by modulating GRN levels. These findings hold promise for the development of future protective therapies for FTLD.

A prospective study of the effectiveness of early intervention with high-risk back-injured workers--a pilot study

INTRODUCTION

It was postulated that workers, at the sub-acute stage after injury, respond differently to clinical and occupational interventions offered in a workers' compensation environment. Individual worker risk of disability, it was further believed, would influence the effectiveness of early intervention. The objective of the current pilot study was to evaluate return to work (RTW) outcomes following proactive, combined clinical, occupational and case management-based interdisciplinary early intervention, provided in a workers' compensation environment 4-10 weeks of onset of back pain, to workers with medium and high risk for disability.

METHODS

The project was a controlled study comparing conventional workers' compensation case management with integrated, interdisciplinary and multimodal early intervention (hereinafter referred to as "EI"). At baseline, risk status was determined by a validated Risk for Disability Questionnaire by Carragee et al. (Spine 5(1):24-35, 2005). Seventeen workers at high risk of protracted disability and 20 workers at moderate risk of disability received conventional case management, and 17 workers assessed at high risk of protracted disability and 18 workers at moderate risk of disability received the Early Intervention.

RESULTS

At 3 months post back pain onset, no statistically significant differences were identified in RTW outcomes between conventional case management and the Early Intervention. However, by 6 months post back pain onset, workers at high risk of work disability who received the Early Intervention were significantly more likely to RTW than high risk workers who received conventional case management. In contrast, moderate risk workers continued to exhibit no statistically significant differences in RTW outcomes.

CONCLUSION

Multimodal Early Intervention in the workers' compensation case management context is likely effective for workers with sub-acute back pain who are at high risk of occupational disability. The comprehensive Early Intervention is, however, likely redundant for workers who are not at high risk for disability and should not be applied indiscriminately. Further studies are required to determine longer-term Early Intervention outcomes, and to replicate the findings using a randomized control design. Also, with a larger sample size, it will be possible to determine predictors of occupational outcomes.

Fate of embryonic stem cells transplanted into the deafened mammalian cochlea

Spiral ganglion neurons (SGNs), the primary afferent neurons of the cochlea, degenerate following a sensorineural hearing loss (SNHL) due to lack of trophic support normally received from hair cells. Cell transplantation is emerging as a potential strategy for inner ear rehabilitation, as injected cells may be able to replace damaged SGNs in the deafened cochlea. An increase in the number of surviving SGNs may result in improved efficacy of cochlear implants (CIs). We examined the survival of partially differentiated mouse embryonic stem cells (MESCs), following xenograft transplantation into the deafened guinea pig cochlea (n=15). Cells were delivered directly into the left scala tympani via microinjection through the round window. Small numbers of MESCs were detected in the scala tympani for up to 4 weeks following transplantation and a proportion of these cells retained expression of neurofilament protein 68 kDa in vivo. While this delivery method requires refinement for effective long-term replacement of damaged SGNs, small numbers of MESCs were capable of survival in the deafened mammalian cochlea for up to 4 weeks, without causing an inflammatory tissue response.