Pollen grains and plant spores have emerged as a novel biomaterial for a broad range of applications including oral drug and vaccine delivery, catalyst support, and removal of heavy metals. However, before pollens can be used, their intrinsic biomolecules, which occupy a large part of the pollen inner cavity must be removed not only to create empty space but because they have potential to cause allergies when used in vivo. These intrinsic materials in the pollen core can be extracted through a chemical treatment to generate clean pollen shells. The commonly used method involves a series of sequential treatments with organic solvents, alkalis, and acids to remove the native pollen biomolecules. This method, though successful for treating lycopodium (Lycopodium clavatum) spores, fails for other species of pollens such as common ragweed (Ambrosia elatior) and thus prevents widespread investigation of different pollens. Herein, we report a new chemical treatment for obtaining clean pollen shells from multiple plant species. This new method involves sequential treatment with acetone, phosphoric acid, and potassium hydroxide. Scanning electron micrographs and protein quantification have shown that the new method can successfully produce clean, intact, and hollow shells from many pollen species including ragweed, sunflower, black alder, and lamb’s quarters. These results demonstrate the broad applicability of this method to clean pollens of different species, and paves the way to start investigating them for various applications.

中文翻译：

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获得洁净完整的不同物种花粉壳的化学处理方法

花粉粒和植物孢子已成为一种新型生物材料，具有广泛的应用，包括口服药物和疫苗输送、催化剂载体和重金属去除。然而，在使用花粉之前，必须去除占据花粉内腔大部分的内在生物分子，这不仅是为了创造空的空间，而且因为它们在体内使用时有可能引起过敏。花粉核中的这些内在物质可以通过化学处理提取出来，产生干净的花粉壳。常用的方法包括用有机溶剂、碱和酸进行一系列连续处理，以去除天然花粉生物分子。这种方法虽然可以成功处理石松 ( Lycopodium clavatum ) 孢子，但无法处理其他种类的花粉，例如普通豚草 ( Ambrosia elatior )，从而阻碍了对不同花粉的广泛研究。在此，我们报告了一种新的化学处理方法，可以从多种植物物种中获得干净的花粉壳。这种新方法涉及用丙酮、磷酸和氢氧化钾进行连续处理。扫描电子显微照片和蛋白质定量表明，新方法可以成功地从豚草、向日葵、黑桤木和羔羊角等许多花粉物种中产生干净、完整和空心的壳。这些结果证明了该方法对清洁不同物种花粉的广泛适用性，并为开始研究它们的各种应用铺平了道路。