Further structural characterization of ovine forestomach matrix and multi-layered extracellular matrix composites for soft tissue repair.

Decellularized extracellular matrix (dECM)-based biomaterials are of great clinical utility in soft tissue repair applications due to their regenerative properties. Multi-layered dECM devices have been developed for clinical indications where additional thickness and biomechanical performance are required. However, traditional approaches to the fabrication of multi-layered dECM devices introduce additional laminating materials or chemical modifications of the dECM that may impair the biological functionality of the material. Using an established dECM biomaterial, ovine forestomach matrix, a novel method for the fabrication of multi-layered dECM constructs has been developed, where layers are bonded via a physical interlocking process without the need for additional bonding materials or detrimental chemical modification of the dECM. The versatility of the interlocking process has been demonstrated by incorporating a layer of hyaluronic acid to create a composite material with additional biological functionality. Interlocked composite devices including hyaluronic acid showed improved in vitro bioactivity and moisture retention properties.

TB or not TB? That is the question regarding TB treatment in a remote provincial hospital in Solomon Islands.

INTRODUCTION: Tuberculosis (TB) remains a significant public health challenge in Solomon Islands. Limited healthcare resources, geography, and sociocultural beliefs, coupled with lack of laboratory diagnostic tools, leads to diagnostic and treatment outcome uncertainty. METHODS: Kirakira Hospital (KKH) is the main provincial hospital of Makira-Ulawa Province in Solomon Islands. A retrospective clinical audit of hospitalised TB patients in KKH over a 2-year period between July 2015 and July 2017 was conducted. The cost of TB treatment was estimated by calculating the total number of inpatient bed days of treatment. RESULTS: Data were available for 42 of 78 listed TB patients including 23 males and 19 females, and 9 children aged less than 16 years. The average age was 35 years (range 9 months - 74 years). Thirty-five of these received a chest X-ray. All patients had at least one of the following: fever, night sweats, chronic cough and haemoptysis as part of their clinical TB presentation. Thirty-six completed the full 8-week duration of intensive HRZE treatment as inpatients of KKH. The audit shows the treatment of TB consumes 15% of the current healthcare budget of Makira-Ulawa Province. CONCLUSION: TB remains a common clinical diagnosis in KKH. TB consumes 15% of the current healthcare budget of Makira-Ulawa Province. The limited capacity and data about the management of TB in Makira province mean that it is not currently possible to measure if there has been any progress towards eradicating TB in Solomon Islands. Laboratory investigations for TB available in Makira including sputum analysis and the GeneXpert are required to improve the accuracy of diagnosis and identify multidrug resistant strains of TB. This needs to be coupled with robust monitoring and data collection of both inpatients and outpatients to ensure the current treatment protocols for TB are being followed in Makira-Ulawa Province. These steps are essential if TB is to be eradicated from the provinces of Solomon Islands by 2030.

Ionic silver functionalized ovine forestomach matrix - a non-cytotoxic antimicrobial biomaterial for tissue regeneration applications.

BACKGROUND: Antimicrobial technologies, including silver-containing medical devices, are increasingly utilized in clinical regimens to mitigate risks of microbial colonization. Silver-functionalized resorbable biomaterials for use in wound management and tissue regeneration applications have a narrow therapeutic index where antimicrobial effectiveness may be outweighed by adverse cytotoxicity. We examined the effects of ionic silver functionalization of an extracellular matrix (ECM) biomaterial derived from ovine forestomach (OFM-Ag) in terms of material properties, antimicrobial effectiveness and cytotoxicity profile. METHODS: Material properties of OFM-Ag were assessed by via biochemical analysis, microscopy, atomic absorption spectroscopy (AAS) and differential scanning calorimetry. The silver release profile of OFM-Ag was profiled by AAS and antimicrobial effectiveness testing utilized to determine the minimum effective concentration of silver in OFM-Ag in addition to the antimicrobial spectrum and wear time. Biofilm prevention properties of OFM-Ag in comparison to silver containing collagen dressing materials was quantified via in vitro crystal violet assay using a polymicrobial model. Toxicity of ionic silver, OFM-Ag and silver containing collagen dressing materials was assessed toward mammalian fibroblasts using elution cytoxicity testing. RESULTS: OFM-Ag retained the native ECM compositional and structural characteristic of non-silver functionalized ECM material while imparting broad spectrum antimicrobial effectiveness toward 11 clinically relevant microbial species including fungi and drug resistant strains, maintaining effectiveness over a wear time duration of 7-days. OFM-Ag demonstrated significant prevention of polymicrobial biofilm formation compared to non-antimicrobial and silver-containing collagen dressing materials. Where silver-containing collagen dressing materials exhibited cytotoxic effects toward mammalian fibroblasts, OFM-Ag was determined to be non-cytotoxic, silver elution studies indicated sustained retention of silver in OFM-Ag as a possible mechanism for the attenuated cytotoxicity. CONCLUSIONS: This work demonstrates ECM biomaterials may be functionalized with silver to favourably shift the balance between detrimental cytotoxic potential and beneficial antimicrobial effects, while preserving the ECM structure and function of utility in tissue regeneration applications.

Novel MRI of mediastinal masses: internal differentiation of a thymoma and lymphoma with T1 and T2 mapping.

Routine imaging for mediastinal malignancies includes chest X-ray, CT or MRI. T1 and T2 mapping are novel MRI techniques which may have a role in expanding the assessment of internal tumour characteristics. This case report details two middle-aged women who had similar clinical presentations of mediastinal masses of comparable size and appearance when assessed with routine imaging. T1 and T2 maps were acquired on MRI to investigate whether these tumours could be further differentiated prior to surgery. T1 and T2 mapping supported suspicion for which tumour components were solid and cystic, as subsequently confirmed histologically. Furthermore, comparison between the two tumours showed native T1 values differed within the solid components by 37%, correlating to differences in proteinaceous material within the tumour types. This radiological-pathological correlation provides evidence that T1 and T2 mapping has clinical utility in the assessment and differentiation of mediastinal masses.