RESUMO
External surface engineering of metal-organic framework nanoparticles (MOF NPs) is emerging as an important design strategy, leading to optimized chemical and colloidal stability. To date, most of the MOF surface modifications have been performed either by physical adsorption or chemical association of small molecules or (preformed) polymers. However, most of the currently employed approaches cannot precisely control the polymer density, and dynamic modifications at the surfaces on demand have been a challenging task. Here, we introduce a general approach based on covalent modification employing alkoxyamines as a versatile tool to modify the outer surface of MOF nanoparticles (NPs). The alkoxyamines serve as initiators to grow polymers from the MOF surface via nitroxide-mediated polymerization (NMP) and allow dynamic attachment of small molecules via a nitroxide exchange reaction (NER). The successful surface modification and successive surface polymerization are confirmed via time-of-flight secondary ion mass spectrometry (ToF-SIMS), size exclusion chromatography (SEC), and nuclear magnetic resonance (NMR) spectroscopy. The functionalized MOF NPs exhibit high suspension stability and good dispersibility while retaining their chemical integrity and crystalline structure. In addition, electron paramagnetic resonance spectroscopy (EPR) studies prove the dynamic exchange of two different nitroxide species via NER and further allow us to quantify the surface modification with high sensitivity. Our results demonstrate that alkoxyamines serve as a versatile tool to dynamically modify the surface of MOF NPs with high precision, allowing us to tailor their properties for a wide range of potential applications, such as drug delivery or mixed matrix membranes.
RESUMO
BACKGROUND: Self-management strategies are considered a necessary component of chronic musculoskeletal pain management to address ongoing symptoms and challenges. However uptake of self-management can be impeded by a number of factors. OBJECTIVES: The aim of this study was to explore common impeding and facilitating factors of self-management strategies from the patient perspective. METHODS: An electronic search was performed between 2009 to May 2020 for the following databases: MEDLINE, AMED, PsychINFO, Cochrane Library, PubMed, CINAHL, PEDro, and Google Scholar. The search terms included peer-reviewed qualitative or mixed-method studies investigating the perspective of chronic musculoskeletal pain patients in regards to the use of self-management strategies. Study rigor and bias was assessed using the CASP (Critical Appraisal Skills Programme) questionnaire specific to qualitative studies. Qualitative data was coded using a three-stage thematic synthesis process. Confidence in findings was assessed using CERQual (The Confidence in the Evidence from Review of Qualitative Research). RESULTS: Twenty-seven studies were included with 487 participants. Six major themes were identified and divided into external and internal influencing factors. The external influencing factors were made up of the following three themes: health care practitioner role, supportive environment, accessibility. While the three internal influencing themes were: physical factors, knowledge and understanding, and psychological factors. CONCLUSION: Learning to self-manage for patients in chronic pain required ongoing support either from healthcare practitioners or from social circles. To further assist the self-management process practitioners can improve self-efficacy through increasing patient knowledge of chronic pain, utilising goal setting and finding ways an individual can access ongoing support, either from the practitioner or through group programs.
