Working with serialized data in Wordpress
I am unable to unserialize your example (did you paste it in correctly?) but Wordpress uses serialize() to serialize objects to store them in the database.
You can unserialize them using unserialize().
A quick example:
$serialized = 'a:3:{i:0;s:5:"apple";i:1;s:6:"banana";i:2;s:6:"orange";}';var_dump(unserialize($serialized));Output:
Array( [0] => apple [1] => banana [2] => orange)