A review of www.clinicaltrials.gov shows that there are several different studies being conducted in the US by various groups. Almost all of them are designed only to determine if the procedure is safe for people. If you decide to pursue one of these studies, don't be surprised if you are asked to pay for the privilege of participating. Paying for participating in a clinical trial turns out to be both legal and ethical; however, most clinical trials are designed and constructed so that the patient donates their time or is paid for various aspects of the research.
If you choose to participate, please remember that there is no scientific, clinical evidence that the procedure makes any difference at all to patients; all the evidence I've seen has been anecdotal by the patients who've participated.
Cellular research has already provided some remarkable results and I do believe that it holds the best hope for either a permanent "fix" or a cure for COPD. I don't believe that any of these current trials will contribute much to our knowledge or lead to additional research.
Jean