When Paula Hammond stepped onto MIT’s campus as a first-year student in the early 1980s, she questioned whether she truly belonged there. In a recent lecture, she candidly shared her feelings of being an “imposter” in her new environment.
Yet, her doubts were soon dispelled as she discovered a supportive community among her peers and faculty. “What mattered most was finding my place and the encouragement I received from those around me,” Hammond reflected.
A distinguished chemical engineer, Hammond delivered her insights during the 2023-24 James R. Killian Jr. Faculty Achievement Award lecture. This prestigious award, established in 1971 in honor of MIT’s 10th president, recognizes exceptional professional accomplishments by faculty members. Hammond was lauded for her remarkable contributions as well as her authentic warmth, leadership capacities, and ethical principles, according to the award citation.
“Professor Hammond stands as a pioneering figure in nanotechnology,” remarked Mary Fuller, chair of MIT’s faculty and a professor of literature, during the award presentation. “Her research spans basic science to tangible impacts in medicine and energy, particularly in developing advanced drug delivery systems for cancer and non-invasive imaging.”
In January, Hammond took on the role of MIT’s Vice Provost for Faculty after chairing the Department of Chemical Engineering for eight years. She was appointed as an Institute Professor in 2021.
A Versatile Technique
Growing up in Detroit, Hammond attributes her love for science to her parents. Her father was among the few Black PhDs in biochemistry during his time, while her mother, a Howard University alumna, established the nursing school at Wayne County Community College. “My parents created immense opportunities for women, particularly women of color,” Hammond emphasized.
After completing her undergraduate studies at MIT in 1984, Hammond worked as an engineer before returning as a graduate student and achieving her PhD in 1993. Following a postdoctoral fellowship at Harvard, she joined the MIT faculty in 1995.
Central to her research is a technique she pioneered that enables the creation of thin films designed to “shrink-wrap” nanoparticles. By adjusting the chemical composition of these films, she has achieved the ability to tailor drug or nucleic acid delivery to specific cellular targets, including cancer cells.
Hammond describes the process starting with the application of positively charged polymers on a negatively charged surface. These layers can be added alternately, utilizing layers that can contain drugs or other essential molecules like DNA or RNA. Depending on the application, the films can consist of various layers—some containing hundreds, others just one.
“One of the strengths of the layer-by-layer technique is my capacity to select biodegradable polymers that are biocompatible, which allows me to alternate these with our drug materials,” she explained. “This enables the creation of complex, multifunctional films through a simple water-based method.”
Hammond elaborated on how these films can stimulate bone growth, which could aid individuals with congenital bone defects or traumatic injuries.
Her lab developed films that incorporate two key proteins: BMP-2, which encourages adult stem cell transformation into bone cells, and VEGF, a growth factor that enhances new blood vessel formation supporting bone regeneration. These films are applied to a thin tissue scaffold implanted at injury sites.
They engineered the scaffold to release VEGF initially over one week while BMP-2 is gradually released over 40 days. In studies with mice, this approach significantly promoted new bone generation that closely resembled natural bone.
Targeting Cancer
As part of MIT’s Koch Institute for Integrative Cancer Research, Hammond is refining layer-by-layer coatings to enhance the performance of nanoparticles in cancer drug delivery, such as liposomes or polymers like PLGA.
“I liken our approach to that of a gobstopper, with multiple layers dissolving sequentially,” Hammond stated. By utilizing this strategy, she’s developed particles capable of delivering a dual-action approach against cancer cells. Initially, these particles release a nucleic acid, such as short interfering RNA (siRNA), to silence a cancerous gene, followed by the release of a chemotherapy agent like cisplatin.
Furthermore, these particles include a negatively charged “stealth layer” that shields them from premature breakdown in the bloodstream, ensuring they reach their cancer cell targets. This outer layer can be tailored to enhance cellular uptake by attaching molecules that latch onto tumor cell proteins.
In her ongoing research, Hammond has aimed to create nanoparticles targeting ovarian cancer while preventing its recurrence post-chemotherapy. Although about 70% of ovarian cancer patients respond well to initial treatments, approximately 85% experience tumor recurrence with high drug resistance.
Hammond has modified the coatings on drug-delivery nanoparticles to enable them to either permeate tumor cells or adhere to their surfaces. By focusing on particles that bind to tumor cells, she has generated treatments that may activate a patient’s immune response against these recurrent cells.
“Ovarian cancer presents a challenge due to the lack of immune cells in the tumor environment, making it tough to incite an immune reaction,” she noted. “If we can target nearby cells and stimulate them, we might create a more potent immune response.”
To facilitate this, she has designed nanoparticles to deliver IL-12, a cytokine stimulating T cells to combat tumor cells. Her mouse studies have shown this treatment could induce a lasting T-cell memory response that reduces the likelihood of ovarian cancer recurrence.
Hammond concluded her lecture by reflecting on the profound influence MIT has had on her life and career. “My journey here has been transformative. This institution fosters collaboration, bringing together individuals to achieve what we couldn’t accomplish in isolation. The support from colleagues, friends, and students truly makes the remarkable possible,” she shared.
Photo credit & article inspired by: Massachusetts Institute of Technology
