HTML centric jargon, the &[something], is the problem. Each character of a "&[something] has a defined value that maps to Unicode. That is what PDF works with (Ref. ISO 32000-1).
Try using the actual ANSI number for the characters. Again, PDF is not HTML.
ANSI 0169 for ©
ANSI 0174 for ®
ANSI 0153 for ™
that worked. I used the chr() function in php. Admittedly though, the trademark symbol still didn't work, but all others are coming through loud n clear.