US4840891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Encapsulation of sperm for artificial insemination
Assignee: BTG International Inc
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Filing: 1986-09-03
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Granted: 1989-06-20
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Expires: 2006-09-03
Abstract
Abstract Sperm are encapsulated in a nontoxic polymer which is freely flowing at body temperature and a gel or solid at temperatures of storage and transfer. On delivery to the reproductive tract, the polymer microcapsule liquifies and the sperm are released.
Inventors
- 👤 Jonathan van Blerkom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:03
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/42; A61B17/425; A61B17/43; A01; A01N; A01N1/00; A01N1/10; A01N1/12; A01N1/128; A61D; A61D19/00; A61D19/02; A61D19/022
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
104 words
A method of encapsulating viable mammalian sperm for storage or transfer, and subsequent insemination of a female mammal, which comprises encapsulating the sperm with a nontoxic hydrophilic polymer, said polymer being essentially freely flowable at the temperature of the uterus of such mammal, but not freely flowable at the temperature of storage or transfer, the polymer at the latter temperature being permeable to molecules of a predetermined size but not to the sperm whereby the sperm may receive nutrients and excrete waste products through the microcapsule without escaping; the sperm escaping from the microcapsule at said uterine temperature when the polymer becomes freely flowable.
Claim 2
Independent Claim
104 words
A method of encapsulating viable mammalian sperm for storage or transfer, and subsequent insemination of a female mammal, which comprises encapsulating the sperm with a nontoxic hydrophilic polymer, said polymer being essentially freely flowable at the temperature of the uterus of such mammal, but not freely flowable at the temperature of storage or transfer, the polymer at the latter temperature being permeable to molecules of a predetermined size but not to the sperm whereby the sperm may receive nutrients and excrete waste products through the microcapsule without escaping; the sperm escaping from the microcapsule at said uterine temperature when the polymer becomes freely flowable.
Claim 3
Dependent Claim
28 words
The method of claim 1 in which the transition of the polymer to the liquid state is completed within 14 hours after it is brought to 37° C.
Claim 4
Dependent Claim
56 words
The method of claim 1, wherein the sperm are encapsulated by (a) providing viable sperm suspended in a suitable culture medium, (b) adding the polymer to the said sperm suspension, transferring the mixture into molds corresponding to the desired dimensions of the microcapsules, and (c) cooling the mixture until it solidifies into a non-free flowing gel.
Claim 5
Dependent Claim
52 words
A method of inseminating an animal which comprises inseminating a receptive female of a species of animal with the encapsulated sperm of claim 1, said female, permitting the encapsulated sperm to warm to the temperature of the uterus of the female, at which temperature the capsule is liquiified and the sperm released.
Claim 6
Dependent Claim
22 words
The method of claim 4 in which the sperm are first held at a temperature at which the capsule is essentially solid.
Claim 7
Dependent Claim
61 words
An article of manufacture comprising viable sperm of a mammalian species encapsulated in a microcapsule formed by a nontoxic hydrophilic polymer which is essentially solid at 4° C., said sperm being released by liquefaction of said polymer at the temperature of the uterus of females of such species, said sperm remaining capable of fertilizing such females after such encapsulation and release.
Claim 8
Dependent Claim
61 words
An article of manufacture comprising viable sperm of a mammalian species encapsulated in a microcapsule formed by a nontoxic hydrophilic polymer which is essentially solid at 4° C., said sperm being released by liquefaction of said polymer at the temperature of the uterus of females of such species, said sperm remaining capable of fertilizing such females after such encapsulation and release.
Claim 9
Dependent Claim
12 words
The article of claim 4 wherein the polymer is a polyurethane polymer.
Claim 10
Dependent Claim
21 words
The method of claim 7 wherein the polymer is selected from the group consisting of polyurethane polyoxyethylene and polyurethane polyester polymers.
Claim 11
Dependent Claim
27 words
The article of claim 4 in which said microcapsule encloses an atmosphere which is about 5% O 2 , 5% CO 2 and 90% N 2 .
Claim 12
Dependent Claim
20 words
The article of claim 4 in which the polymer is selected from the group consisting of RL39-115, RL39-117, and RL39-118.
Claim 13
Dependent Claim
28 words
The article of claim 4 in which the polymer forms a microcapsule enclosing a culture medium for the sperm, said medium having a pH of about 7.37 -7.42.
Claim 14
Dependent Claim
38 words
The article of claim 4 in which the polymer forms a microcapsule enclosing a culture medium for the sperm, said medium providing calcium lactate in an amount sufficient to render the sperm hypermotile when unrestrained by the microcapsule.
Claim 15
Dependent Claim
21 words
The article of claim 4 where the polymer forms a translucent microcapsule about the sperm, whereby its motility may be observed.
Claim 16
Dependent Claim
34 words
The article of claim 6 wherein the sperm are held in a state of reduced motility and metabolic activity prior to liquefaction, the motility and metabolic activity of the sperm being restored after liquefaction.
Claim 17
Dependent Claim
24 words
The article of claim 6, where more than 50% of the sperm remain viable for 14 days after encapsulation and storage at 40° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |