Anjali Jaiprakash

Phenotypic characterization of osteoarthritic osteocytes from the sclerotic zones: a possible pathological role in subchondral bone sclerosis.

Subchondral bone sclerosis is a well-recognised manifestation of osteoarthritis (OA). The osteocyte cell network is now considered to be central to the regulation of bone homeostasis; however, it is not known whether the integrity of the osteocyte cell network is altered in OA patients. The aim of this study was to investigate OA osteocyte phenotypic changes and its potential role in OA subchondral bone pathogenesis. The morphological and phenotypic changes of osteocytes in OA samples were investigated by micro-CT, SEM, histology, immunohistochemistry, TRAP staining, apoptosis assay and real-time PCR studies. We demonstrated that in OA subchondral bone, the osteocyte morphology was altered showing rough and rounded cell body with fewer and disorganized dendrites compared with the osteocytes in control samples. OA osteocyte also showed dysregulated expression of osteocyte markers, apoptosis, and degradative enzymes, indicating that the phenotypical changes in OA osteocytes were accompanied with OA subchondral bone remodelling (increased osteoblast and osteoclast activity) and increased bone volume with altered mineral content. Significant alteration of osteocytes identified in OA samples indicates a potential regulatory role of osteocytes in subchondral bone remodelling and mineral metabolism during OA pathogenesis.

A stimulatory effect of Ca3ZrSi2O9 bioceramics on cementogenic/osteogenic differentiation of periodontal ligament cells

The regeneration of periodontal tissues to cure periodontitis remains a medical challenge. Therefore, it is of great importance to develop a novel biomaterial that could induce cementogenesis and osteogenesis in periodontal tissue engineering. Calcium silicate (Ca-Si) based ceramics have been found to be potential bioactive materials due to their osteostimulatory effect. Recently, it is reported that zirconium modified calcium-silicate-based (Ca3ZrSi2O9) ceramics stimulate cell proliferation and osteogenic differentiation of osteoblasts. However, it is unknown whether Ca3ZrSi2O9 ceramics possess specific cementogenic stimulation for human periodontal ligament cells (hPDLCs) in periodontal tissue regeneration in vitro. The purpose of this study was to investigate whether Ca3ZrSi2O9 ceramic disks and their ionic extracts could stimulate cell growth and cementogenic/osteogenic differentiation of hPDLCs; the possible molecular mechanism involved in this process was also explored by investigating the Wnt/β-catenin signalling pathway of hPDLCs. Our results showed that Ca3ZrSi2O9 ceramic disks supported cell adhesion, proliferation and significantly up-regulated relative alkaline phosphatase (ALP) activity, cementogenic/osteogenic gene expression (CEMP1, CAP, ALP and OPN) and Wnt/β-catenin signalling pathway-related genes (AXIN2 and CTNNB) for hPDLCs, compared to that of β-tricalcium phosphate (β-TCP) bioceramic disks and blank controls. The ionic extracts from Ca3ZrSi2O9 powders also significantly enhanced relative ALP activity, cementogenic/osteogenic and Wnt/β-catenin-related gene expression of hPDLCs. The present results demonstrate that Ca3ZrSi2O9 ceramics are capable of stimulating cementogenic/osteogenic differentiation of hPDLCs possibly via activation of the Wnt/β-catenin signalling pathway, suggesting that Ca3ZrSi2O9 ceramics have the potential to be used for periodontal tissue regeneration.

Design and fabrication of a disposable micro end effector for concentric tube robots

Conventional concentric tube robots (CTRs) have low dexterity at the tip, which does not fit the requirements of complicated operations in minimally invasive surgery. A 2mm diameter cable-driven micro end effector is designed and fabricated for CTRs to increase dexterity in confined spaces. The end-effector is made by a simple fabrication procedure and is a combination of readily available materials such as polyolefin tube, acrylic and steel strings. If mass produced, the end effector has the potential to be made into a single use disposable medical tool. This paper discusses the geometric design, fabrication process and force analysis of the end effector. Experiments are conducted on the prototype to validate the derivation. In addition, cases are discussed around the use of the end effector.

Unlocking the Value of Literature in Health Co-Design: Transforming Patient Experience Publications into a Creative and Accessible Card Tool

BackgroundA wealth of peer-reviewed data exists regarding people’s health experience, yet practical ways of using the data to understand patients’ experiences and to inform health co-design are needed.ObjectiveThis study aims to develop an applied and pragmatic method for using patient experience literature in co-design by transforming it into an accessible and creative co-design tool.MethodA scoping literature review of the CINAHL, MEDLINE, PsycINFO and PubMed electronic databases was conducted from January 2011 through August 2016. Qualitative publications regarding the experience of living with diabetes in Australia were selected. The Results section of each paper was extracted and affinity analysis was applied to identify insights into the health experience. These insights were developed into a card tool for use in health co-design activities.ResultsThirteen relevant papers were identified from the review, and affinity analysis of the Results sections of these papers lead to the identification of 85 insights, from ‘Shock of diagnosis’ (Insight 1), to ‘Delay seeking care’ (Insight 9), to ‘Assess the quality of care’ (Insight 28), to ‘Avoid or adapt habits’ (Insight 78). Each insight was developed into an individual card, which included a high-level theme, insight, quote and a link back to the literature, together making up the Health Experience Insight Cards, Living with Diabetes Edition.ConclusionsThis was the first study to develop a method for transforming existing patient experience literature into a creative tool for health improvement. The Health Experience Insight Cards collate the diverse experiences of over 300 people living with diabetes in Australia, from 13 studies. Health improvement teams can use the ‘Living with Diabetes Edition’ cards or they can follow this pragmatic method to create their own cards focused on other health experiences to facilitate person-focused health improvements.

Evaluation of Keypoint Detectors and Descriptors in Arthroscopic Images for Feature-Based Matching Applications

Knee arthroscopy is a very challenging surgical procedure that would strongly benefit from systems that can continuously map the inside of the knee, localize the arthroscope and surgical tools, and control instruments using visual information. A fundamental requirement of most of these systems is the correct and fast matching of visual features. Feature-based systems have been demonstrated in laparoscopy but have yet to be extended to the context of arthroscopy. As an essential initial step, this letter proposes the first detailed experimental evaluation of the performance of state-of-the-art feature detection and description methods on arthroscopic images. We first evaluate the behavior of eight keypoint detectors under 133 setting combinations using four different metrics in a dataset with 100 in-vivo images. We then combine the previous detectors with six feature descriptors and evaluate the matching performance for the resulting features (detector+descriptor) across five different image transformations. A validation is performed using in-vivo images acquired under varying camera motion and illumination. The results show that the best-performing feature in knee-arthroscopy images is DoG+SIFT, while features BRISK+SURF and BRISK+BRISK are recommended for viable implementations in real time.

Implant Surface Modifications and Osseointegration

Osseointegration and osteogenic differentiation are important determinants of clinical outcomes involving implants in orthopaedics and dentistry. Implant surface microstructure and hydrophilicity are known to influence these properties. Recent research has focused on several modifications of surface topography and chemistry aimed at improving bone formation to achieve faster and better healing. Topographically modified titanium implant surfaces, like the sandblasted, large-grit, acid-etched (SLA) surface and chemically modified hydrophilic SLA (modSLA) surface, have shown promising results when compared with smooth/polished titanium surfaces. Although most studies consider an average roughness (Ra) of 1–1.5 μm to be favourable for bone formation, there is no consensus regarding the appropriate roughness and chemical modifications necessary to achieve optimal osseointegration. Studies on microstructurally modified surfaces have revealed intricate details pertaining to the molecular interactions of osteogenic cells with implant surfaces. The in vivo and in vitro findings from these studies highlight the ability of modified titanium surfaces to support the establishment of a native osteogenic niche for promoting bone formation on the implant surfaces. Improved osteogenic properties of modified surfaces are evidenced in vitro by the differential regulation of the molecular transcriptome on such surfaces. Recent studies indicate that post-transcriptional modulators like microRNAs also play an important role in osteogenic regulation on implant surfaces. In this chapter, we discuss the current concepts and considerations in orthopaedic and dental implant research and the new knowledge in the field, which will assist in the development of novel approaches and designs of future implant devices.