Even minor lesions in articular cartilage (AC) can cause underlying bone damage creating an osteochondral (OC) defect. OC defects can cause pain, impaired mobility and can develop to osteoarthritis (OA). OA is a disease that affects nearly 10% of the population worldwide[1], and represents a significant economic burden to patients and society[2]. While significant progress has been made in this field, realising an efficacious therapeutic option for unresolved OA remains elusive and is considered one of the greatest challenges in the field of orthopaedic regenerative medicine[3]. Therefore, there is a societal need to develop new strategies for AC regeneration. In recent years there has been increased interest in the use of tissue-specific aligned porous freeze-dried extracellular matrix (ECM) scaffolds as an off-the-shelf approach for AC repair, as they allow for cell infiltration, provide biological cues to direct target-tissue repair and permit aligned tissue deposition, desired in AC repair[4]. However, most ECM-scaffolds lack the appropriate mechanical properties to withstand the loads passing through the joint[5]. One solution to this problem is to reinforce the ECM with a stiffer framework made of synthetic materials, such as polylactic acid (PLA)[6]. Such framework can be 3D printed to produce anatomically accurate implants[7], attractive in personalized medicine. However, typical 3D prints are static, their design is not optimized for soft-hard interfaces (OC interface), and they may not adapt to the cyclic loading passing through our joints, thus risking implant failure. To tackle this limitation, more compliant or dynamic designs can be printed, such as coil-shaped structures[8]. Thus, in this study we use finite element modelling to create different designs that mimic the mechanical properties of AC and prototype them in PLA, using polyvinyl alcohol as support. The optimal design will be combined with an ECM scaffold containing a tailored microarchitecture mimicking aspects of native AC.
Collagen is a key component of the extracellular matrix in a variety of tissues and hence is widely used in tissue engineering research, yet collagen has had limited uptake in the field of 3D printing. In this study we successfully adapted an existing electronic printing method, aerosol jet printing (AJP), to print high resolution 3D constructs of recombinant collagen type III (RHCIII). Circular samples with a diameter of 4.5mm and 288 layers thick, or a diameter of 6.5mm and 400 layers thick were printed on glass cover slips with print lines of 60µm. Attenuated Total Reflectance Fourier-Transorm Infa-red (ATR-FTIR) spectroscopy performed on the 4 of the printed samples and dried non-printed RHCIII samples showed that no denaturation had occurred due to the printing process. Printed samples were crosslinked using EDC [N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride, Sigma Aldrich] to improve their stability and mechanical strength. Differential scanning calorimetry (DSC) performed showed a marked difference in the denaturation temperature between crosslinked printed samples and fibrillar non-printed samples and nano-indentation showed that the construct was relatively stiff. Previous results with similar samples have shown that mesenchymal stem cells (MSCs) align with and travel parallel to print direction. Results obtained from these samples show signs that they might be applied in other areas such as bone tissue engineering.
Few doctors answer their bleep by stating who they are. Answering the phone in a formal manner is of utmost importance in the hospital setting especially by on-call teams who are normally referred patients by other specialties, general practitioners and in some cases by other hospitals. An audit to evaluate the internal hospital communication was completed. In the first part of this audit, junior doctors within the orthopaedic department at the RAH were bleeped. Doctors were expected to answer by initiating the conversation by stating (1) name, (2) department, (3) grade and (4) a greeting. A list of omissions was recorded. If the call went through switchboard, it was expected that the hospital name was stated. The second part of the audit extended to other specialties in the RAH as well as orthopaedic departments in hospitals within the Greater Glasgow and Clyde health board (NHS GGC). Forty-three bleeps were made to doctors of various grades over a period of two months. Nine bleeps (two from other hospitals) were not answered. Five doctors answered their bleep in full. Only twenty-one doctors stated their name whilst eleven stated their grade. In both instances the department was not necessarily stated. The results were similar between the different departments as well as between the seven hospitals offering an orthopaedic service within NHS GGC. Of the thirteen on-call doctors that were bleeped as an external call through switchboard, only one doctor stated the hospital name. This has implications since most hospitals within NHS GGC share a common switchboard. These results emphasise the need for a protocol within NHS GGC for a standard etiquette for intra and inter hospital communication to ensure that patient safety and confidentiality is safeguarded.
