$re = '/(https:\/\/vk\.com.+\b(?<!\.png))$/m';
$str = 'https://vk.com/images/iemoj/D83DDE0E.png
fdsfds https://vk.com/sadovodxasanov vcxfdsfds
fdsfdsfdf https://vk.com/id080845122210 fdsfdsffds
';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php