PMMA Bone Cement Composite Functions as an Adjuvant Chemotherapeutic Platform for Localized and Multi-Window Release during Bone Reconstruction.

Primary bone tumor resections often result in critical size defects, which then necessitate challenging clinical management approaches to reconstruct. One such intervention is the Masquelet technique, in which poly(methyl methacrylate) (PMMA) bone cement is placed as a spacer temporarily while adjuvant chemotherapeutics are administered systemically. The spacer is later removed and replaced with bone autograft.

Recent Advances in the Evaluation of Antimicrobial Materials for Resolution of Orthopedic Implant-Associated Infections .

While orthopedic implant-associated infections are rare, revision surgeries resulting from infections incur considerable healthcare costs and represent a substantial research area clinically, in academia, and in industry. In recent years, there have been numerous advances in the development of antimicrobial strategies for the prevention and treatment of orthopedic implant-associated infections which offer promise to improve the limitations of existing delivery systems through local and controlled release of antimicrobial agents. Prior to translation to orthopedic implant-associated infection models, the properties (, degradation, antimicrobial activity, biocompatibility) of the antimicrobial materials can be evaluated in subcutaneous implant models.

Characterization of Inflammatory and Fibrotic Encapsulation Responses of Implanted Materials with Bacterial Infection.

Medical device infections are costly, while preclinical assessment of antimicrobial properties for new materials is time intensive and imperfect at capturing the interrelated aspects of infection response and wound resolution. Herein, we developed an in vivo model for quantification of inflammatory and biocompatibility responses in the presence of a sustained implant-associated infection. The antimicrobial effectiveness of commercially available polymer materials was compared to that of thermoplastic polyurethane (TPU) materials modified with putative antimicrobial strategies as example test materials.

Modified Cyclodextrin Microparticles to Improve PMMA Drug Delivery Without Mechanical Loss.

Antibiotic-loaded poly(methyl methacrylate) (PMMA) cement is commonly used as a local delivery system to treat and prevent orthopedic infections associated with arthroplasties in load-bearing applications. However, these delivery systems are inefficient as release rate sharply declines to subinhibitory levels. Prior studies have shown that by adding in drug-filled cyclodextrin (CD) microparticles into PMMA cement, a more consistent release is observed, and antibiotic refilling through simulated implantation can be achieved.

Poly(methyl methacrylate) Bone Cement Composite Can Be Refilled with Antibiotics after Implantation in Femur or Soft Tissue.

While periprosthetic joint infections (PJIs) result in a small percentage of patients following arthroplasties, they are challenging to treat if they spread into bone and soft tissue. Treatment involves delivering antibiotics using poly(methyl methacrylate) (PMMA) bone cement. However, antibiotic release is insufficient for prolonged infections.

Antibiotic Refilling, Antimicrobial Activity, and Mechanical Strength of PMMA Bone Cement Composites Critically Depend on the Processing Technique.

Antibiotic-laden poly(methyl methacrylate) (PMMA) bone cement is used in a variety of applications including temporary spacers for load-bearing arthroplasties and non-load bearing orthopedic revision procedures and antibiotic beads to treat infections. Depending upon the surgical preparation technique, properties of PMMA can widely vary. The primary objective of this work was to perform an in-depth structure-function analysis regarding how processing of PMMA impacted material and structural properties (i.

A Polymeric Delivery System Enables Controlled Release of Genipin for Spatially-Confined In Situ Crosslinking of Injured Connective Tissues.

An emerging approach toward repair of connective tissues applies exogenous crosslinkers to mechanically augment injured structures in vivo. One crosslinker that has been explored for this purpose is the plant-derived small molecule genipin. However, genipin's high reactivity to primary amines in proteins, small size, and high diffusion coefficient necessitate localizing and controlling its delivery to avoid off-target or adverse effects.

Nonthermal plasma treatment of polymers modulates biological fouling but can cause material embrittlement.

Plasma-based treatment is a prevalent strategy to alter biological response and enhance biomaterial coating quality at the surfaces of biomedical devices and implants, especially polymeric materials. Plasma, an ionized gas, is often thought to have negligible effects on the bulk properties of prosthetic substrates given that it alters the surface chemistry on only the outermost few nanometers of material. However, no studies to date have systematically explored the effects of plasma exposure on both the surface and bulk properties of a biomaterial.

Combination Antibiotic Delivery in PMMA Provides Sustained Broad-Spectrum Antimicrobial Activity and Allows for Postimplantation Refilling.

Antibiotics are commonly added to poly(methyl methacrylate) (PMMA) by surgeons to locally treat infections such as in bone cement for joint replacement surgeries, as well as implantable antimicrobial "beads". However, this strategy is of limited value in high-risk patients where infections can be recurrent or chronic and otherwise hard to treat. Also, when only one drug is incorporated and applied toward polymicrobial infections (multiple bacterial species), there is a high risk that bacteria can develop antibiotic resistance.

Use of affinity allows anti-inflammatory and anti-microbial dual release that matches suture wound resolution.

Surgical sutures are vulnerable to bacterial infections and biofilm formation. At the suture site, pain and undesirable, excess inflammation are additionally detrimental to wound healing. The development of a polymerized cyclodextrin (pCD) coated surgical suture introduces the capability to locally deliver both anti-inflammatory and anti-microbial drugs throughout the phases of acute and chronic healing.

Woven collagen biotextiles enable mechanically functional rotator cuff tendon regeneration during repair of segmental tendon defects in vivo.

Despite advancements in surgical techniques and materials for rotator cuff repair procedures, primary repair failures remain common. This study examines the use of electrochemically aligned collagen (ELAC) threads woven into biotextile scaffolds as grafts to repair critical infraspinatus tendon defects in New Zealand White rabbits. Three surgical treatment groups were evaluated: rabbits undergoing direct repair as operative controls, rabbits receiving ELAC scaffolds alone, and rabbits treated with mesenchymal stem cell (MSC)-seeded ELAC scaffolds.

An Additive to PMMA Bone Cement Enables Postimplantation Drug Refilling, Broadens Range of Compatible Antibiotics, and Prolongs Antimicrobial Therapy.

Poly(methyl methacrylate) (PMMA) bone cement is used in several biomedical applications including as antibiotic-filled beads, temporary skeletal spacers, and cement for orthopedic implant fixation. To mitigate infection following surgery, antibiotics are often mixed into bone cement to achieve local delivery. However, since implanted cement is often structural, incorporated antibiotics must not compromise mechanical properties; this limits the selection of compatible antibiotics.