A biomaterial and its potential degradation products should be biocompatible, nontoxic, and removed by the body upon expiration of its functional lifetime. One historically successful approach is to create new materials from biomolecules that naturally occur in the human body. Herein, we report the synthesis and characterization of a polycarbonate based on dihydroxyacetone, a 3-carbon ketose, and an intermediate in the glucose metabolic pathway. The polymer was synthesized in a range of molecular weights ( approximately 8000 to approximately 37,500) by ring-opening polymerization. The C2 carbonyl of dihydroxyacetone is reactive to amines, and this reactivity was used to functionalize the polymer's surface in a one-step reaction by reductive amination. Additionally, contact angle measurements show the surface of poly(2-oxypropylene carbonate) is hydrophilic even though it is insoluble in water. Mechanical analysis of the polymer revealed it is exceptionally strong for an aliphatic polycarbonate. Specifically, poly(2-oxypropylene carbonate), M(w) 37 500, yielded a Young's modulus of 0.5 GPa and a compressive yield stress of 50 MPa. These values equal or exceed those of cancellous bone with similar dimensions.

We report the design of an injectable synthetic and biodegradable polymeric biomaterial comprised of polyethylene glycol and a polycarbonate of dihydroxyacetone (MPEG-pDHA). MPEG-pDHA is a thixotropic physically cross-linked hydrogel, displays rapid chain relaxation, is easily extruded through narrow-gauge needles, biodegrades into inert products, and is well tolerated by soft tissues. We demonstrate the clinical utility of MPEG-pDHA in the prevention of seroma, a common postoperative complication following ablative and reconstructive surgeries, in an animal model of radical breast mastectomy. This polymer holds significant promise for clinical applicability in a host of surgical procedures ranging from cosmetic surgery to cancer resection.hydrogel | seroma prevention | dihydroxyacetone | surgical biomaterial P olymeric biomaterials have contributed significantly to the advancement of medical and surgical practice over the past few decades. Their macromolecular structure can be tailored to provide the appropriate combination of chemical, physical, and biological properties necessary for a range of medical and surgical applications. The rational design of polymeric biomaterials has impacted many fields, including drug and gene delivery, orthopedics, tissue engineering, ophthalmology, and general surgery (1-3). The work reported herein focuses on the development of an injectable surgical biomaterial. Its potential impact is demonstrated in the prevention of postoperative seroma.A seroma is an abnormal collection of serous fluid within the tissues of the body, akin to an internal blister. Seroma formation is a common postoperative complication particularly following ablative and reconstructive surgeries. Surgeries that require extensive tissue dissection and create large empty spaces can disrupt normal lymphatic flow. Subsequently, transduate fluid collects in these poorly drained "dead spaces," resulting in formation of a seroma (4, 5). Seromas can lead to significant patient morbidity, such as infection, decreased limb mobility, and reoperation (4, 6, 7). Seroma formation rates range from 9.1% to 81%, depending on the nature of the surgical procedure (6,(8)(9)(10)(11)(12)(13). Notably, modified radical mastectomies lead to seroma formation rates ranging from 15% to 38.6%, and radical mastectomies report a rate as high as 52% (7,(14)(15)(16)(17). In current clinical practice, silicone surgical drains are placed in the wound bed through separate stab incisions to collect transudate fluid, but they can be a significant source of pain and discomfort to patients, especially upon their removal up to several weeks after the initial surgical procedure. Furthermore, they can increase the risk of infection at the surgical site.Several approaches to reduce seroma formation have been investigated. Surgical techniques, such as collapsing the seroma cavity with sutures, do not consistently and adequately eliminate seroma formation (16,18,19). Other methods, such as sclerotherapy (20, 21), compression dressings (22), and biolog...

The synthesis of new polymeric biomaterials using biocompatible building blocks is important for the advancement of the biomedical field. We report the synthesis of statistically random poly(carbonate-ester)s derived from lactic acid and dihydroxyacetone by ring-opening polymerization. The monomer mole feed ratio and initiator concentration were adjusted to create various copolymer ratios and molecular weights. A dimethoxy acetal protecting group was used to stabilize the dihydroxyacetone and was removed using elemental iodine and acetone at reflux to produce the final poly(lactide-co-dihydroxyacetone) copolymers. The characteristics of the copolymers in their protected and deprotected forms were characterized by (1)H NMR, (13)C NMR, GPC, TGA, and DSC. Hydrolytic degradation of the deprotected copolymers was tracked over an 8-week time frame. The results show that faster degradation occurred with increased carbonate content in the copolymer backbone. The degradation pattern of the copolymers was visualized using SEM and revealed a trend toward surface erosion as the primary mode of degradation.