Therapeutic calcium phosphate particles and methods of manufacture and use

Abstract

Novel calcium phosphate core particles, methods of making them, and methods of using them as vaccine adjuvants, as cores, as carriers of biologically active material, and as controlled release matrices for biologically active material are disclosed. The core particles may have a surface modifying agent and / or biologically active material, such as antigenic material or natural immunoenhancing factor, polynucleotide material, or therapeutic proteins or peptides, partially coating the particle or impregnated therein. The core particles have a diameter between about 300 nm and about 4000 nm, more particularly between about 300 nm and about 2000 nm, and even more particularly between about 300 nm and about 1000 nm, are substantially spherical in shape, and have a substantially smooth surface

Description

[0001] This application claims benefit of the filing dates of U.S. Provisional Application Ser. Nos. 60 / 118,356; 60 / 118,364; and 60 / 118,355, all filed Feb. 3, 1999, the entire contents of each of which are hereby incorporated by reference.BACKGROUND OF INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to novel calcium phosphate core particles, to methods of making them, and to methods of using them as vaccine adjuvants, as cores or carriers for biologically active material, and as controlled release matrices for biologically active material. [0004] 2. Description of Related Art [0005] Nanometer scale particles have been proposed for use as carrier particles, as supports for biologically active molecules, such as proteins, and as decoy viruses. See U.S. Pat. Nos. 5,178,882; 5,219,577; 5,306,508; 5,334,394; 5,460,830; 5,460,831; 5,462,750; and 5,464,634, the entire contents of each of which are hereby incorporated by reference. [0006] The particles disclo...

AI Technical Summary

Benefits of technology

[0029] One embodiment of the present invention relates to methods of adjuvanting vaccines, whether live, killed, attenuated, a decoy virus, or made from core particles at least partially coated with microbial antigenic material, or combinations thereof, by administering the novel uncoated core particles or core particles coated with natural immunoenhancing factor to a patient in need of vaccination either alone or in combination or conjunction with administration of the vaccine. The core particles are sufficiently small to be easily transportable to various tissues throughout the body, and are biodegradable as well.

[0030] The invention also relates to methods of vaccinating patients in need thereof by administering the novel core particle in combination or in conjunction with an antigenic material or natural immunoenhancing factor, wherein the antigenic material or natural immunoenhancing factor is at least partially coated on the core particle and / or integrated therein, as described in more detail below. The calcium phosphate core particles of this embodiment significantly increase the efficacy of the vaccines with which they are administered, by enhancing the magnitudes, qualities, and / or durations of the immune responses.

[0031] In another embodiment, the invention also relates to a polynucleotide vaccine having polynucleotide material at least partially coated on the novel core particle and / or impregnated therein. Contrary to conventional wisdom, the present inventors have discovered novel calcium phosphate particles that can be effectively used as supports and matrices for sustained release of DNA or RNA encoding immunogenic polypeptides. The present inventors have discovered that a DNA or RNA vaccine can be prepared that uses a biodegradable matrix of calcium phosphate, that functions as a sustained release composition, conferring long lasting immunity, and that is, in effect, self-adjuvanting. The primary intent is that the respective protein translation products produced by the present invention would immediately be available both intracellularly and extracellularly, to elicit enhanced humoral and cellular immune responses.

[0032] When administered as a polynucleotide vaccine, the calcium phosphate in the core particles of the present invention biodegrades, releasing into the surrounding tissue polynucelotide material (DNA or RNA) coding for immunogenic polypeptides. Without wishing to be bound to any theory, it is believed that cells in the patient take up the DNA or RNA and express it as immunogenic proteins, which are then presented to B cells and T cells of the immune system, resulting in both a humoral and cell-mediated response similar to that obtained using live attenuated virus, but without the risks of pathogenicity and without the loss of immunogenicity associated with live virus. When the DNA or RNA is impregnated or dispersed within the calcium phosphate core particle, the gradual release of genetic material by the dissolution of the calcium phosphate matrix provides longer lasting immune responses than does administration of a conventional DNA or RNA vaccine.

[0033] In addition, while not wishing to be bound by any theory, it is believed that the presence of calcium phosphate core particles enhances the immune response to the antigenic proteins produced by the cells that take up and express the DNA or RNA, further multiplying the protective effect of the vaccine. The size of the core particles of the invention allows them to migrate through the body as the calcium phosphate gradually degrades, thereby transporting the DNA / RNA to different tissues in the body, and enlisting large numbers of different tissues at different locations in the production of antigenic proteins.

[0035] The present invention also relates to methods of treating medical conditions resulting from protein or peptide deficiencies by administering effective amounts of the core particles of this particular embodiment to a patient in need thereof via inhalation into the lungs. The therapeutic compositions of the present invention are highly stable, and exhibit enhanced bioavailability. These therapeutic compositions also exhibit preferable biodynamics including controlled release of therapeutic polypeptides or proteins.

Problems solved by technology

Particles of this size are difficult to make with any degree of consistency, and their morphology is not described in any detail.

None of these patents disclose the use of nanoparticles as sustained release matrices.

Furthermore, these patents do not disclose the use of calcium phosphate particles as either (1) adjuvants for vaccines or viral decoys, or (2) controlled release matrices for delivery of pharmaceuticals or immunogenic materials.

There has been a suggestion in the literature to use calcium phosphate particles as vaccine adjuvants, but calcium phosphate particles have generally been considered an unsuitable alternative to other adjuvants due to inferior adjuvanting activity.

However, traditional vaccine methodologies may be undesirable as a result of their expense, instability, poor immunogenicity, limited heterogeneity and potential infectivity.

However, this approach may be undesirable for several reasons.

Also, viral vectors and modified pathogens have inherent risks that may hinder their use in humans (R. R. Redfield et al., New Engl. J. Med. 316, 673 (1987); L. Mascola et al., Arch. Intern. Med. 149, 1569 (1989)).

For example, in live vector approaches, highly immunogenic vectors also tend to be highly pathogenic.

Thus, the system described by Wang et al., may be inappropriate for administration to humans.

However, this patent does not suggest the use of calcium phosphate particles as supports for DNA or RNA vaccines.

This patent also fails to suggest the use of calcium phosphate particles as controlled release matrices for genetic material.

For a number of therapeutic agents, delivery of the agent to a patient in need thereof can be difficult.

This is particularly true with proteins and peptides, which are difficult or impossible to administer orally, since they are easily digested or hydrolyzed by the enzymes and other components of gastric juices and other fluids secreted by the digestive tract.

Injection is often the primary alternative administration method, but is unpleasant, expensive and is not well tolerated by patients requiring treatment for chronic illnesses.

In particular, patients who are administered drugs on an out-patient basis, or who self-administer, are more likely to fail to comply with the required administration schedule.

However, preparation of suitable inhalable aerosols can be difficult for therapeutic agents where the blood level of the agent is critical, e.g., with insulin, because the amount of aerosol delivered to the deep lung tissue can be substantially variable, leading to inconsistent dosages of the drug to the patient.

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