Method of creating biocompatible polymeric resin systems for bone repair and management
Inventors
Kollarigowda, Ravichandran • Kolan, Krishna • Saadatmanesh, Neda • Saadatmanesh, Hamid • Srinivasan, Abiraman
Assignees
Publication Number
US-11925401-B1
Publication Date
2024-03-12
Expiration Date
2043-05-04
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Abstract
A photocurable device injection system for creating in situ polymerization via light or free-radical to enable fractured bone fixation. The system comprises a photosensitive polymeric resin sensitive to light, temperature, oxygen, enzymes, or a combination thereof. The photosensitive polymeric resin may be configured to cure at room temperature or physiological temperature with a light source. The photosensitive polymeric resin may be configured to depolymerize with ultrasonication, sonication, or a combination thereof. The system further comprises an implantable 3-dimensional biocompatible pouch comprising an optical light guide. The system further comprises one or more micro-sized ultrasonication probes configured to contact a three-dimensional pouch by one or more openings. The one or more probes may be configured to enable polymer outflow.
Core Innovation
The invention features a photocurable injection system designed for the in-situ polymerization of a photocurable polymeric resin to enable fractured bone fixation and allow for removal of the cured polymer via pulverization and extraction. This system comprises a photosensitive polymeric resin that can cure at room or physiological temperature, activated by an external light source or free radicals, and can be depolymerized or removed using ultrasonication or sonication. The polymeric resin includes functional materials adapted to cure into a stiff, pulverizable polymer with minimal volumetric shrinkage (less than 2%), matching the stiffness of load-bearing bone and exhibiting low exothermic heat.
The system also includes an implantable three-dimensional biocompatible sleeve device comprising one or more openings with access ports and an optical light guide with a diffusive tip for transmitting curing light. A minimally invasive ultrasonic system with micro-sized probes is configured to enter the sleeve and pulverize and extract the cured polymer particles through laparoscopic openings, thereby allowing removal of the implant in a minimally invasive manner.
The invention addresses the clinical problem of current bone fracture treatments which often require invasive surgeries that cause significant trauma, risk thermal necrosis due to exothermic curing of bone cements, and entail difficult removal procedures involving metal implants and secondary surgeries. Existing bone cements have issues with high volumetric shrinkage and difficulty in removal. The invention solves these problems by providing a minimally invasive system with a polymeric resin that matches bone properties, cures in situ at controlled temperatures with minimal shrinkage, and can be removed safely using ultrasonic pulverization, thus reducing trauma, risk of infection, and recovery time.
Additionally, the invention includes methods to select and customize polymeric resin formulations and the curing process potentially using machine learning and artificial intelligence based on patient-specific factors such as age, bone density, fracture region, and fracture classification. This enables a tailored approach for orthopedic biomaterial treatments with a system designed to integrate with the host anatomy and allow therapeutic benefits while ensuring ease of removal or permanent implantation.
Claims Coverage
The patent includes two independent claims covering a photocurable injection system and the composition of the photocurable polymeric resin with specific functional materials and features enabling bone fixation and minimally invasive removal.
Photocurable polymeric resin with functional materials
A polymeric resin comprising functional materials adapted to photocure into a stiff, pulverizable cured polymer, with functional materials acting as monomers, comonomers, cross-linkers, or combinations thereof.
Minimally invasive ultrasonic extraction system
An ultrasonic system configured to pulverize the cured polymer into particles and extract said particles through laparoscopic openings using micro-sized probes.
Specific resin composition formulation
A resin formulation comprising approximately 75-80% polymethylmethacrylate (PMMA) resin solution, 10-15% isobornyl methacrylate, 1-10% diurethane dimethacrylate, 0.1-5% ethylene glycol dimethacrylate, and 0.1-5% polycaprolactone dimethacrylate, capable of in-situ photocuring and exhibiting minimal volumetric shrinkage.
Photoinitiator activation
The polymeric resin is activated by photoinitiators such as 2-Hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone, diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.
Functional materials enabling pulverizability
Inclusion of diurethane dimethacrylate, ethylene glycol dimethacrylate, and polycaprolactone dimethacrylate functional materials facilitates the cured polymer to be pulverizable, aiding minimally invasive removal.
The claims collectively cover a photocurable bone fixation system featuring a functional polymeric resin that cures in situ into a stiff, pulverizable implant, combined with a minimally invasive ultrasonic extraction system for removal. The inventive features include the specific polymer formulations, photoinitiator activation, and the ability for pulverization and extraction of the cured polymer through laparoscopic approaches, addressing prior limitations in bone fracture treatment.
Stated Advantages
Minimally invasive implantation and removal of bone fixation devices, reducing surgical trauma and rehabilitation time.
Polymeric resin matches the mechanical stiffness of natural bone and exhibits low exothermic heat upon curing, minimizing tissue damage.
The cured polymer shrinks less than 2% in volume, preserving bone alignment and implant integrity.
The system eliminates the need for metal implants, preventing imaging interference and infection risks associated with metal devices.
Ultrasonic pulverization allows safe, efficient removal of the cured polymer implant through small laparoscopic openings.
Customizable material formulation and curing process using AI/machine learning tailored to patient-specific factors.
The use of functional materials enables the resin to be both curable by light and depolymerizable or removable on demand.
Documented Applications
Repair and stabilization of various bone fractures including hand, wrist, radius, ulna, clavicle, metacarpal, phalanx, metatarsal, tibia, fibula, humerus, and rib fractures.
Orthopedic fixation for load-bearing long bones using minimally invasive resins and sleeve systems.
Use in civilian and combat orthopedic trauma management.
Application in veterinary medicine for orthopedic fracture fixation.
Potential use in dental implant removal or other polymer-based implant removals requiring minimally invasive treatment.
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