Sort PHP multidimensional array [Value1],[Value2]

Sort PHP multidimensional array [Value1],[Value2]

I have this Array:
[0] => Array
(
[video_id] => SimpleXMLElement Object
(
[0] => 75071886
)
[tags] => SimpleXMLElement Object
(
[0] => #20, MusicVideos
)
)
[1] => Array
(
[video_id] => SimpleXMLElement Object
(
[0] => 74212195
)
[tags] => SimpleXMLElement Object
(
[0] => #5, MusicVideos
)
)
[2] => Array
(
[video_id] => SimpleXMLElement Object
(
[0] => 37274070
)
[tags] => SimpleXMLElement Object
(
[0] => #9, MusicVideos
)
)
[3] => Array
(
[video_id] => SimpleXMLElement Object
(
[0] => 37277922
)
[tags] => SimpleXMLElement Object
(
[0] => #12, MusicVideos
)
)
Now I would like to sort this array by [tags] How do I do this this PHP?
Using the Online tool [Tags] use to order in my website by i want "#1",
"#2"
But i have one more than one [Tags] Like "#1" and "Category"
Thanks