Continuous digital light processing additive manufacturing of implants
A process for additive manufacturing of a resorbable implant to be implanted into a patient includes providing a biocompatible resin including a liquid light-polymerizable material that is resorbable after polymerization and an initiator. The process further includes actuating an additive manufacturing apparatus to expose an amount of the biocompatible resin to light to at least partially cure the exposed amount of biocompatible resin to form a layer of the resorbable implant and actuating the additive manufacturing apparatus to expose at least some additional amount of biocompatible resin to light to at least partially cure the exposed additional amount of biocompatible resin to form an additional layer of the resorbable implant and to at least partially overcure previously cured layers to cause at least some interlayer binding between the previously cured layers and the additional layer.
1. A composition for a resin used in additive manufacturing of biocompatible medical devices comprising, a photo initiator, a light attenuator which limits transmission of light that activates the photo-initiator in a build direction of the additive manufacturing including by scattering at least some of the light in a second direction different from the build direction, and a light absorber which absorbs at least some of the light scattered in the second direction by the light attenuator, wherein the photo-initiator is an acylphosphine oxide, wherein the light absorber is one or more of a benzophenone, an oxybenzone, or an avobenzone.
2. The composition of claim 1 wherein the light attenuator is TiO2.
3. The composition of claim 1 wherein the photo-initiator is Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (BAPO).
4. The composition of claim 1 wherein the benzophenone is selected from the group consisting of: 2,4-dihydroxybenzophenone, 2,2′,4,4′-tetrahydroxybenzophenone, sulisobenzone, sulixobenzone sodium, 2,2′-dihydroxy-4,4′-dimethyoxybenzophenone, 5-chloro-2-hydroxybenzophenone, dioxybenzone, sodium 2,2′-dihydroxy-4,4′-dimethoxybenzophenone-5,5′-disulfonate, 2-hydroxy -4-methoxy-4′-methyl-benzophenone, benzophenone-2, benzophenone-6, octabenzone, and 2-Hydroxy-4′-methoxybenzophenone (oxybenzone).
5. The composition of claim 1 , wherein the light attenuator is Bis(.eta.5-2,4-cylcopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl) titanium.
6. The composition of claim 5 , wherein the photo-initiator is Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (BAPO).
7. The composition of claim 6 , wherein the light absorber is oxybenzone (2-Hydroxy-4-methoxybenzophenone).
8. The composition of claim 2 wherein the amount of TiO2 is 0.1 to 5.0% by weight of the polymer and solvent.
9. The composition of claim 3 wherein the amount of BAPO is 0.1 to 5.0% by weight of the polymer and solvent.
10. The composition of claim 1 wherein the amount of oxybenzone by weight of the polymer and solvent is about 25 to 35%.
11. The composition of claim 5 wherein the amount of Bis(.eta.5-2,4-cylcopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl) titanium by weight of the polymer and solvent is about 0.1 to 5.0%.
12. The composition of claim 6 wherein the amount of BAPO by weight of the polymer and solvent is about 0.1 to 5.0%.
13. The composition of claim 7 wherein the amount of oxybenzone by weight of the polymer and solvent is about 0.1 to 5.0%.
14. A resin composition used in additive manufacturing of a biocompatible medical device, comprising:
a light attenuator in an amount by weight of the resin composition of about 0.1 to 5.0%,
a photo-initiator in an amount by weight of the resin composition of about 0.1 to 5.0%, wherein the light attenuator is capable of limiting the transmission of light that activates the photo-initiator in a build direction of the additive manufacturing including by scattering at least some of the light in a second direction different from the build direction, and
a light absorber in an amount by weight of the resin composition of about 5 to 25%, wherein the light absorber is capable of absorbing at least some of the light scattered in the second direction by the light attenuator,
wherein the resin composition comprises at least one polymer and at least one solvent,
further comprising a second light attenuator.
15. The resin composition of claim 14 wherein the light attenuator is titanium dioxide.
16. The resin composition of claim 14 wherein the photo-initiator is an acylphosphine oxide.
17. The resin composition of claim 16 wherein the photo-initiator is Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (BAPO).
18. The resin composition of claim 14 wherein the second light attenuator is Bis(.eta.5-2,4-cylcopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl) titanium.
19. The resin composition of claim 14 wherein the light absorber is a benzophenone.
20. The resin composition of claim 19 wherein the light absorber is oxybenzone (2-Hydroxy-4-methoxybenzophenone).
21. A light-polymerizable composition for use in additive manufacturing of biocompatible medical devices, comprising a biocompatible polymer, a solvent, and a biocompatible light attenuator in an amount of about 0.1-5% by weight of the polymer and solvent, a biocompatible photo-initiator in an amount of about 0.1-5% by weight of the polymer and solvent, and a biocompatible light absorber, wherein the biocompatible light attenuator limits transmission of light that activates the biocompatible photo-initiator in a build direction of the additive manufacturing including by scattering at least some of the light in a second direction different from the build direction, and the biocompatible light absorber absorbs at least some of the light scattered in the second direction by the biocompatible light attenuator, wherein the light absorber is a benzophenone, an oxybenzone, an avobenzone, or combinations thereof.
22. The light-polymerizable composition of claim 21 , wherein the biocompatible light absorber is provided in an amount of about 10-35% by weight of the polymer and solvent.
23. The light-polymerizable composition of claim 21 further comprising a second light attenuator, wherein the second light attenuator is provided in an amount of about 0.1-5% by weight of the polymer and solvent.
24. The light-polymerizable composition of claim 23 wherein the second light attenuator is Bis(.eta.5-2,4-cylcopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl) titanium.
25. The light-polymerizable composition of claim 21 wherein the biocompatible polymer is polypropylene fumarate.
26. The light-polymerizable composition of claim 25 wherein the solvent is diethyl fumarate.