Abstract: A phosphorous compound such as STMP is used as a cross-linking agent while making a starch nanoparticle in an emulsion process. Negative charge of the nanoparticle is reduced or reversed by adding cations and/or cationizing the starch optionally while forming the nanoparticles. Anionic active agents, such as fluoride or fluorescein, are optionally incorporated into the nanoparticle during the formation process. For example, a fluoride salt can also be used, which promotes the crosslinking reaction while also providing fluoride in the nanoparticle. The retention of both calcium and fluoride in the nanoparticle is improved when both salts are used. Alternatively, the nanoparticle may be used without added calcium and/or fluoride. The nanoparticles may be useful for tooth remineralization, the treatment of dentinal hypersensitivity, to treat caries, or as a diagnostic agent to locate carious lesions.

Abstract: This specification describes a dental imaging and/or curing system and methods of using it, optionally in combination with a fluorescent imaging aid applied to a tooth. In some examples, a system or kit described in this specification combines a fluorescent compound with an intra-oral device. The intra-oral device includes a light source to excite the fluorescent compound. The intra-oral device further includes a sensor to produce an image of fluorescent light emitted from the fluorescent compound. Optionally, the fluorescent compound can include positively charged nanoparticles including a fluorophore, for example fluorescein. Optionally, the intra-oral device can include a blue LED, a bandpass emission filter and a digital camera sensor. This specification also describes an intra-oral device and a method of producing an image of plaque, calculus or active carious lesions in the mouth of a person or other animal.

Abstract: A delivery device for a active agent comprises nanoparticles based on a biopolymer such as starch. The delivery device may also be in the form of an aptamer-biopolymer-active agent conjugate wherein the aptamer targets the device for the treatment of specific disorders, such as cancer. The delivery device survives for a period of time in the body sufficient to allow for transport and uptake of the delivery device into targeted cells. The degree of crosslinking can provide a desired release profile of the active agent at, near or inside the target cells. The nanoparticles may be made by applying a high shear force in the presence of a cross linker. The particles may be predominantly in the range of 50-150 nm and form a colloidal dispersion of crosslinked hydrogel particles in water.

Abstract: A delivery device for an active agent comprises nanoparticles based on a biopolymer such as starch. The delivery device may also be in the form of an aptamer-biopolymer-active agent conjugate wherein the aptamer targets the device for the treatment of specific disorders. The nanoparticles may be made by applying a high shear force in the presence of a crosslinker. The particles may be predominantly in the range of 50-150 nm and form a colloidal dispersion of crosslinked hydrogel particles in water. The biopolymer may be functionalized. The aptamer may be conjugated directly to the cross-linked biopolymers. The active agent may be a drug useful for the treatment of cancer. The delivery device survives for a period of time in the body sufficient to allow for the sustained release of a drug and for the transportation and uptake of the conjugate into targeted cells. However, the biopolymer is biocompatible and resorbable.