Table 2.
Overview of oral studies performed with PS-NPs in rats
| NP type | Detection method | Experimental conditions | Dose | Size | Uptake (% of the administered dose) | Ref. |
|---|---|---|---|---|---|---|
| Carboxylated polystyrene nanospheres linked with rhodamine | Fluorescence microscopy observations | Female Sprague–Dawley rats; gavage | 1.25 mg/kg bw, daily for 10 days | 100 nm, 1 µm | Uptake only semiquantitatively quantified: very low uptake in the stomach wall, small intestinal wall and mesentery node; low uptake in the Peyer’s patch, colon and liver; no NPs in kidney, lungs, heart and spleen | Jani et al. (1989) |
| Non-ionized polystyrene microspheres linked with fluorescein | 100 nm, 500 nm, 1 µm, 3 µm | Low uptake in the spleen, stomach wall and small intestinal wall; moderate uptake in liver and colon; high uptake in the Peyer’s patch and mesentery node; no NPs in kidney, lungs and heart | ||||
| Non-ionized polystyrene microspheres linked with fluorescein | Presence of polystyrene was analysed by gel permeation chromatography; measurement of radioactivity of tissues | Female Sprague–Dawley rats; gavage | 1.25 mg/kg bw, daily for 10 days | 50 nm | Total uptake: 33.7 % Without stomach-, small- and large intestinal walls: 6.6 %a Liver: 3.3 % Spleen: 0.9 % Kidney: 0.2 % Stomach wall: 1.1 % Small intestinal wall: 12 % Large intestinal wall: 14 % No NPs in lungs and heart |
Jani et al. (1990) |
| 100 nm | Total uptake: 26 % Without stomach-, small- and large intestinal walls: 5.9 %a Liver: 3.8 % Spleen: 0.7 % Stomach wall: 0.7 % Small intestinal wall: 3.4 % Large intestinal wall: 16 % No NPs in kidney, lungs and heart |
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| 300 nm | Total uptake: 9.5 % Without stomach-, small- and large intestinal walls: 2.7 %a Liver: 1.4 % Spleen: 0.2 % Stomach wall: 0.5 % Small intestinal wall: 2 % Large intestinal wall: 4.3 % No NPs in kidney, lungs and heart |
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| 500 nm | Total uptake: 13.7 % Without stomach-, small- and large intestinal walls: 1.9 %a |
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| 1 µm | Total uptake: 4.6 % Without stomach-, small- and large intestinal walls: 0.8 %a |
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| Non-ionized polystyrene microspheres linked with fluorescein | Fluorescence microscopy observations | Female Sprague–Dawley rats; gavage | 12.5 mg/kg, 6 h | 50 nm | Uptake only semiquantitatively quantified: Significant uptake in the Peyer’s patches and mesentery nodes; no NPs in liver and spleen | Jani et al. (1992) |
| 500 nm | Low uptake in the Peyer’s patches; evident uptake in mesentery nodes; no NPs in liver and spleen | |||||
| 1 µm | Low uptake in the Peyer’s patches; no NPs in mesentery nodes, liver and spleen | |||||
| Carboxylated polystyrene NPs coupled with lectin | Fluorescence microscopy observations; gel permeation chromatography | Female Wistar rats; gavage | 12.5 mg/kg, daily for 5 days | 500 nm | Total estimated uptake: 37.6 %a
Without stomach-, small- and large intestinal walls: 23 % Liver: 2.6 % Spleen: 1.2 % Heart: 0.3 % Kidney: 0.7 % Intestinal wall: 12.8 % |
Hussain et al. (1997) |
| With N-acetylchitotetraose | Spleen: 0.42 % | |||||
| Non-ionized polystyrene NPs with covalently linked fluorescein, coated with 407 poloxamer | Fluorescence microscopy observations; gel permeation chromatography | Female Sprague–Dawley rats; gavage | 14 mg/kg, daily for 5 days | 60 nm | Uptake across the GI tract: 3 %: Lymphoid large intestine: 2.0 % Non-lymphoid large intestine: 1 % |
Hillery and Florence (1996) |
| Coated with 188 poloxamer | Uptake across the GI tract: 1.5 %: Lymphoid large intestine: 1.5 % |
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| Non-ionized polystyrene NPs with covalently linked fluorescein | Fluorescence microscopy observations; gel permeation chromatography | Female Sprague–Dawley rats, 9 weeks, oral gavage | 14 mg/kg, daily for 5 days | 60 nm | Uptake across the GI tract: 10 %: Lymphoid small intestine: 3.4 % Non-lymphoid small intestine: 2.3 % Lymphoid large intestine: 3.0 % Non-lymphoid large intestine: 2.2 % |
Hillery et al. (1994) |
| Polystyrene NPs, FITC-labelled | Fluorescence microscopy observations | Male Wistar rats: Young (5 weeks); intraduodenally administered, single dose | 3.7 × 109 in 1 ml, 6 h | 1 µm | Measured in lymph fluid: −2 × 10−6 %a | Seifert et al. (1996) |
| Middle age (5 months) | −2 × 10−5 %a | |||||
| Old (9 months) | −1.4 × 10−5 %a |
aCalculated from the numbers given in the manuscript