The goal of this clinical research study is to evaluate the safety and tolerability of injecting certain cells that you produce in your bone marrow called mesenchymal stem cells (MSCs) into your salivary glands.

Participants will have head and neck cancer that was treated with radiation therapy, and in this study will:

• Undergo a collection of bone marrow using a needle;
• Donate saliva;
• Undergo a salivary gland ultrasound; and,
• Complete questionnaires that ask about dry mouth

Participants can expect to be in this study for up to 30 months.

There is no expanded access program available per this protocol.

Inclusion Criteria:

• History of histological diagnosis of head and neck cancer (HNC) that was treated with radiation therapy and currently clinically or radiologically no evidence of disease (NED)
• Xerostomia, defined as patient reported salivary function (pre-treatment) ≤ 80% of healthy (pre-radiation)
• ≥ 18 years of age, ≤ 90 years of age.
• Patients ≥ 2 years from completion of radiation therapy for HNC
• Karnofsky performance status ≥ 70, patient eligible for bone marrow aspirate with wakeful anesthesia
• Willing and able to give informed consent
• Radiographically confirmed submandibular gland(s)

Exclusion Criteria:

• Salivary gland disease (i.e., sialolithiasis)