1. Pluronic Hydrogel in Post Lumpectomy Breast Reconstruction
Pluronic hydrogels being used in post lumpectomy breast reconstruction–
One specific application of these hydrogels is the ability of them to be used in this
*important to note the distinction between lumpectomy and mastectomy
Solomon Swartz & Sana Majid

2. Outline Scope of the Problem Science of Hydrogels
Treatment for Breast Cancer
Reconstruction
Science of Hydrogels
Clinical Applications
Looking Forward

3. Breast Cancer 12.5% of women will be affected within their lifetime
Breast cancer death rates are the 2nd highest cancer death rates in women
2.7 million alive in the US with a history of breast cancer
Offer some background on the scope of breast cancer
Death rates are second only to lung cancer

4. Treatment for Breast Cancer
Chemotherapy
Radiation
Lumpectomy
Full or partial mastectomy
Many different methods of treating breast cancer, including but not limited to the methods listed above. One very common procedure is a lumpectomy. Lumpectomy involves the removal of lump or tumor from the affected breast tissue and is often considered to result in minimal deformation of the breast. This generally leads to breast asymmetry, which can be of significant concern to the patients. There are known psychological benefits to surgeries reestablishing the symmetry in the breasts. Breast reconstruction can be very important for the mental well being of these individuals

5. Current Reconstruction Techniques
Autologous Procedures
Pros: Little rejection, reformation of the breast, minimal complications
Cons: Expensive, long procedures, surgery required
No prosthetic implants currently available for lumpectomy patients
The key is that these are lumpectomy procedures, and all prosthetics implants that are currently available only work for mastectomy patients. Autologous procedures are pretty much the only option for lumpectomy patients. These procedures are generally expensive

6. Brief Introduction to Hydrogels
First developed in the 1950s by Wichterle and Lim
Valued for:
Low Toxicities
Abilities to absorb excess water
Relative cost-effectiveness
Ease of manufacture
Polaxomers (Pluronics) were later synthesized in 1973

7. Pluronics Thermosensitive
Cold=liquid
Warm=solid
Rise in temperatures cause degradation of H-bonding of ester bonds in PPO, causing micelle formation
Reversible process
Sol-gel transition temperatures vary based on polymer segment lengths and concentration
Unique tri-block copolymer structure provides
Explain a little bit of the chemistry behind it here The two outer polymer chains consist of hydrophilic Poly-ethylene oxide while the inner chain consists of poly-propylene oxide
Unique property of propylene oxide– hydrophilic at low temperatures but hydrophobic at higher temperatures
viscosity change rate may also vary based on additions of other hydrogel components

8. How it Works Hydrogels will degrade over time– need to prolong this
Can’t use traditional cross-linking methods
Divalent calcium ion, used for sustained drug delivery, can’t be used due to its disruption of X-ray
Following a partial mastectomy, patients may require follow-up X-ray of the damaged area.
Modification of the pluronic to enable cross-linkage via radiation treatment
The crosslinking reaction is irreversible
After modifications, the gel is no longer completely thermoreversible, which slows down the degradation process, but doesn’t halt it
Serve as cell carriers for tissue regeneration– because the pluronics will degrade over time, we want it to serve as a scaffold for tissue regrowth and have growth factors (HGH?) to allow that to happen
Different hydrogel brands carry different types of cells—human adipose tissue-derived precursor cells?
Can also contain adult stem cells

9. Clinical Applications
Applied non- invasively via hypodermic needle and syringe
Solution is injected cold as a liquid and natural body temperatures cause the solution to self-assemble in-vivo.
Thermosensitivity of pluronics enables this material to be applied non-invasively via hypodermic needle and syringe.
Following either lumpectomy or partial mastectomy, the solution is injected cold as a liquid and natural body temperatures cause the solution to self-assemble in-vivo.
Must be performed prior to radiation treatment to enable effective cross-linking of the micelle matrix

10. Clinical Applications
Pros
Cons
No surgery
Less infection
Mechanical properties of gel mimic native breast tissue
Cost Effective
No maintenance required
Not applicable for mastectomy or large partial mastectomy patients
Currently not tested clinically for viability
Autologous procedures are generally much more expensive, as they require a length surgery which is often quite complicated and can have problems. Autologous procedures also have donor site morbidity and secondary site infection
Cost: Still in clinical trials so we don’t know if ti will yet be covered by insurance, but it is very affordable to it will likely be an option

11. Looking Forward Improvements Complications Breast Symmetry
Increased self-confidence
Potential for Tissue Regeneration
Psychological Benefits
Inflammation
Failure to cross-link
Required readministration

12. References
Elluru, M., et al. “Synthesis and characterization of biocompatible hydrogel using Pluronics-based block copolymers.” Polymer. 54 (2013): Web.