Thanks for writing, I had this same question last year. After working for about 5 years in the cosmetic/formulation industry, I decided to go to back for a masters as a means to pursue a PhD in biomedical sciences. My undergrad GPA was a 2.82 thus my initial hesitation to pursue grad school. I decided to pursue a masters first and now have a 3.75 GPA to add to my CV. I'll also be doing a thesis and TAing next semester too. I'm hoping that the few patents that I'm on plus the graduate classes plus the time in between undergrad and grad school will help me get into a good PhD program.
Anyways, with a similar background, I can let you know how I fair with my applications next semester. Best of luck!