The use of Acceptance and Commitment Therapy to address psychological distress experienced by caregivers: a randomised controlled feasibility trial

Background: An extensive research literature has documented the impact of caring for an individual with acquired brain injury (ABI) on caregivers and family members, including role adjustment, psychological distress, social isolation, family tension and coping with the cognitive and behavioural difficulties of the injured person. Given these findings it is important this population have access to services and supports. Acceptance and Commitment Therapy (ACT) is an intervention that helps individuals to accept difficult experiences and commit to behaviour that is consistent with their values. Research into the effectiveness of ACT to support caregivers is at a preliminary stage. Aim: To investigate the feasibility of using ACT to reduce psychological distress and increase psychological flexibility in ABI caregivers. A secondary aim was to gain an understanding of the experience of caregivers in this context and how this can inform the development and delivery of interventions for this population. Method: Phase one was a randomised controlled feasibility trial of an ACT intervention for use with ABI caregivers. The parameters of this study were formulated around the PICO (population, intervention, control, and outcome) framework. Eighteen carers were recruited and randomised to ACT or an enhanced treatment as usual (ETAU) group. ACT was implemented over 3 sessions; and ETAU was implemented over 2 sessions. The General Health Questionnaire, Valuing Questionnaire, Acceptance and Action Questionnaire, Experiential Avoidance of Caregiving Questionnaire and the Flexibility of Responses to Self-Critical Thoughts Scale were administered to both groups at baseline and following the final session. Phase two used a retrospective qualitative design that involved conducting semi-structured interviews with four participants from phase one. Results: ACT and control participants were successfully recruited. Positive feedback was obtained from ACT participants suggesting that the intervention was acceptable. There were no significant differences between the ACT and ETAU groups on outcome measures. However, there were challenges retaining participants and the overall attrition rate was high (44.44%). Therefore a number of participants did not complete the full complement of sessions, which may have impacted on this result. Qualitative results illustrated the challenges this population face including significant adjustments in their life, the emotional impact of having a loved one with a brain injury and trying to adapt to the changes in the injured person. In addition, findings elucidated the types of support that this population would find helpful and the barriers to accessing same. Conclusions: Findings from this study highlight factors that will help the development of this intervention further for a caring population. Recommendations for future implementation include completing some preparatory work with carers before beginning the intervention, consideration of a larger sample and wider recruitment strategy from local services, barriers to attending interventions and the possibility of holding groups in local venues.

Controlled surface nanotopography and oxygen plasma treatment of PEEK to improve cellular response

Poly(aryl-ether-ether-ketone) (PEEK) is a semi crystalline polymer which exhibits properties that make it an attractive choice for use as an implant material. It displays natural radiolucency, and MRI compatibility, as well as good chemical and sterilization resistance, both of which make it of particular interest in orthopaedic implants. However, PEEK has demonstrated poor cellular adhesion both in vitro and in vivo. This is problematic as implant surfaces that do not develop a layer of adhesive cells are at risk of undergoing fibrous encapsulation, which in turn leads to lack of a strong interface between the implant device and the patient tissue, which can in turn lead to failure of the implant and revision surgery . As incorporating nanotopography into a polymer surface has been demonstrated to be able to direct the differentiation behaviour of stem cells, a possible solution to PEEKs underlying issues with poor cellular response would be to incorporate specific nanoscale topography into the material surface through injection moulding, and then analysing if this is a viable method for addressing PEEKs issues with cellular response. In addition to nanoscale topography, the experimental PEEK surfaces were treated with oxygen plasma to address the underlying cytophobicity of the material. As this type of treatment has been documented to be capable of etching the PEEK surface, experiments were carried out to quantify the effect of this treatment, both on the ability of cells to adhere to the PEEK surface, as well as the effect it has upon the nanotopography present at the PEEK surface. The results demonstrated that there were a range of plasma treatments which would significantly improve the ability of cells to adhere to the PEEK surface without causing unacceptable damage to the nanotopography. Three different types of cells with osteogenic capacity were tested with the PEEK surfaces to gauge the ability of the topography to alter their behaviour: SAOS-2, osteoprogenitors and 271+ MSCs. Due to PEEKs material properties (it is non transparent, exhibits birefringence and is strongly autofluorescent) a number of histological techniques were used to investigate a number of different stages that take place in osteogenesis. The different cell types did display slightly different responses to the topographies. The SAOS-2 cells cultured on surfaces that had been plasma treated for 2 minutes at 200W had statistically significantly higher levels of von Kossa staining on the NSQ surface compared to the planar surface, and the same experiment employing alizarin red staining, showed a statistically significantly lower level of staining on the SQ surface compared to the planar surface. Using primary osteoprogenitor cells designed to look into if whether or not the presence of nanotopography effected the osteogenic response of these cells, we saw a lack of statistically significant difference produced by the surfaces investigated. By utilising HRP based immunostaining, we were able to investigate, in a quantitative fashion, the production of the two osteogenic markers osteopontin and osteocalcin by cells. When stained for osteocalcin, the SQ nanotopography had total percentage of the surface with stained material, average area and average perimeter all statistically significantly lower than the planar surface. For the cells that were stained for osteopontin, the SQ nanotopgraphy had a total percentage of the surface with stained material, average area and average perimeter all highly statistically significantly lower than those of the planar surface. Additionally, for this marker the NSQ nanotopography had average areas and average perimeters that were highly significantly higher than those of the planar surface. There were no significant differences for any of the values investigated for the 271+ MSC’s When plasma treatment was varied, the SAOS-2 cells demonstrated an overall trend i.e. increasing the energy of plasma treatment in turn leads to an increase in the overall percentage of staining. A similar experiment employing stem cells isolated from human bone marrow instead of SAOS-2 cells showed that for polycarbonate surfaces , used as a control, mineralization is statistically significantly higher on the NSQ nanopattern compared to the planar surface, whereas on the PEEK surfaces we observe the opposite trend i.e. the NSQ nanotopography having a statistically significantly lower amount of mineralization compared to the planar surface at the 200W 2min and 30W 1min plasma treatments. The standout trend from the PEEK results in this experiment was that the statistically significant differences on the PEEK substrates were clustered around the lower energy plasma treatments, which could suggest that the plasma treatment disrupted a function of the nanotopograhy which is why, as the energy increases, there are less statistically significant differences between the NSQ nanotopography and the Planar surface This thesis documents the response of a number of different types of cells to specific nanoscale topographies incorporated into the PEEK surface which had been treated with oxygen plasma. It outlines the development of a number of histological methods which measure different aspects of osteogenesis, and were selected to both work with PEEK, and produce quantitative results through the use of Cell Profiler. The methods that have been employed in this body of work would be of interest to other researchers working with this material, as well as those working with similarly autofluorescent materials.