I loaded a renderable array within a hook_block_view. I need to add a prefix and suffix to the title before rendering it. How can I manage to do that ?
You have an error in the very title. Adding prefixes and suffixes is not a job for a module. You do it in template. If you need to wrap it in html tags, do it in
node.tpl.php. If you need some more elaborated logic, see template_preprocess_node().