For biomedical application of nanoparticles, the surface chemical functionality is very important to impart additional functions, such as solubility and stability in a physiological environment, and targeting specificity as an imaging probe and a drug carrier. Although polyethylene glycol (PEG) has been used extensively, here, it is proposed that hyperbranched polyglycerol (PG) is a good or even better alternative to PEG. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared using a polyol method are directly functionalized with PG through ring‐opening polymerization of glycidol. The resulting SPION‐PG is highly soluble in pure water (>40 mg mL−1) and in a phosphate buffer solution (>25 mg mL−1). Such high solubility enables separation of SPION‐PG according to size using size exclusion chromatography (SEC). The size‐separated SPION‐PG shows a gradual increase in transverse relaxivity (r2) with increasing particle size. For biological application, SPION‐PG is functionalized through multistep organic transformations (–OH → –OTs (tosylate) → –N3 → –RGD) including click chemistry as a key step to impart targeting specificity by immobilization of cyclic RGD peptide (Arg‐Gly‐Asp‐D‐Tyr‐Lys) on the surface. The targeting effect is demonstrated by the cell experiments; SPION‐PG‐RGD is taken up by the cells overexpressing αvβ3‐integrin such as U87MG and A549.

The solid state transformation of chitin β into chitin α under the influence of aqueous HCl of increasing concentration was investigated in the case of highly crystalline β chitin microfibrils isolated from the vestimentiferan tube of Tevnia jerichonana. With acid strength below 6 N, the chitin microfibrils remained un-affected. With acid strength between 6 and 7 N a total decrystallization was observed when the samples were immersed in the acid solution. When the initial β chitin was washed, crystals or one of their hydrates was restored, but the initially large microfibrils of chitin became split into a series of parallel subfibrils of much smaller diameter. With acid strength from 7 N to 8 N, decrystallization was also observed but it was accompanied by a substantial cutting and dissolution of the chitin chains. These smaller chains recrystallized in epitaxy on the remaining β chitin microfibrils in a subsequent washing step. In this case, the recrystallization led to morphologies resembling those of shish kebab where the “kebab” overgrowths consisted of α chitin spindle-like crystals organized in epitaxy on the underlying β chitin microfibrillar remainder. When acid strengths of 8 N and above were used, the sample recrystallized exclusively as α chitin upon washing. As opposed to the case where lower acid concentration was used, a total loss of the fibrillar morphology was observed with HCl of 8 N and above.