Cartridge safety injection system and methods

A system for injecting, comprising:

• a cartridge body having proximal and distal openings, and a distal cartridge body interface;
• a distal cartridge seal removably coupled to the distal cartridge body interface of the cartridge body, the distal cartridge seal defining
• a longitudinal channel extending longitudinally through the distal cartridge seal, and
• a sealing gland extending radially into the longitudinal channel:
• a stopper member disposed in a cartridge interior of the cartridge body;
• a plunger member having a plunger interior and configured to be manually manipulated to insert the stopper member relative to the cartridge body, the plunger member including
• a needle retention feature disposed in the plunger interior,
• an energy-storage member disposed in the plunger interior, and
• an energy-storage member latching member disposed in the plunger interior;
• and
• a needle hub assembly coupled to the distal cartridge body interface of the cartridge body, the needle hub assembly including
• a needle having a needle proximal end feature,
• a hub, and
• a needle latching member configured to selectively prevent the needle from moving proximally relative to the hub,
• wherein manipulating the plunger member relative to the cartridge body to transform the energy-storage member latching member from a latched state to an unlatched state retracts the needle proximal end feature proximally through the stopper member.