2-Hydroxyethyl methacrylate (HEMA)-based (co)polymers showed soluble to insoluble (S–I) thermoresponses, as measured by turbidimetry, when heated in aqueous solutions of appropriate ionic strength and/or pH. Surprisingly, many of the polymers showed a second insoluble to soluble (I–S) thermoresponse at higher temperatures, probably as a result of breaking of polymer–polymer H-bonding that allowed redissolution of the polymer chains. The thermoresponse of the charged copolymers was very sensitive to the polymer concentration, pH, and ionic strength likely due to the role of charge screening in the chain collapse and aggregation necessary to observe cloud points. Urea, a commonly used “H-bond breaker”, raised the cloud point (and decreased the clearing point for systems that showed I–S transitions); however, subsequent cooling or heating runs in the presence of urea often showed dramatically different thermoresponses as a result of urea hydrolysis, leading to a pH change and/or polymer hydrolysis at high temperature. Marked hysteresis or changes from run to run were seen for some systems because of polymer precipitation or slow rehydration of phase-separated material or, in some cases, slow hydrolysis of HEMA units.

While silicone elastomers generally have excellent biomaterials properties, their hydrophobicity can elicit undesired local biological responses through adsorption and denaturation of proteins. Surface-bound poly(ethylene glycol) (PEG) can ameliorate the situation by preventing contact between the external biology and the silicone elastomer. It is further possible to manipulate the biocompatibility of the surface by linking peptides, proteins or other biological entities to the PEG. Previous synthetic approaches to PEG-protected surfaces are compromised by issues of reproducibility. We describe two rapid and efficient approaches to silicone surface modification by PEG-linked adhesion peptides that overcome this problem: SiH groups are introduced throughout a silicone elastomer during elastomer synthesis or only at the surface after cure; then, in either case, protein-repellent PEG brushes at the surface are introduced by hydrosilylation to give surfaces that can be stored for extensive periods of time without degradation. Activation of the free alcohol with an NSC group followed by immediate conjugation to relevant biological molecules occurs in high yields, as shown for RGDS and GYRGDS. High surface grafting density of the peptides was demonstrated using radiolabeling techniques. Biological activity was demonstrated by a 5-fold increase in cell adhesion on the peptide-modified surfaces when compared to unmodified PDMS control surfaces.

Objective: The Systematic Classic/Zhen Jiu Jia Yi Jing (ZJJYJ,) is considered to be the first complete acupuncture manual to detail the location and meridian assignations of 349 acupuncture points. Despite numerous transcriptions and editing changes, many traditional acupuncturists adhere to the classics and rarely question their validity. However, ushering the use of acupuncture into the modern era requires examining acupuncture point locations objectively by comparing contemporary anatomical knowledge with classical texts. The aim of this research was to examine distinct neuroanatomical targets associated with acupuncture points to: (1) standardize the precise neuroanatomical target of each acupuncture point; and (2) crossreference neuroanatomical targets with classical point locations. This was done to demonstrate ancient authors' intentions when describing acupuncture points as coordinates used to stimulate the peripheral nervous system. Materials and Methods: The unique neuroanatomical targets associated with acupuncture points on the Foot Shao Yin Kidney meridian were defined. Specifically, KI 1 through KI 8 were examined by comparing classical point locations from the ZJJYJ with modern standardized textbook locations from Chinese Acupuncture and Moxibustion, current anatomical literature, the current authors' cadaver dissection research, and electrostimulation of acupuncture points in healthy volunteers. Results: KI 1-KI 8 correlated with motor entry points as well as with nerve branches and vessels derived from the posterior tibial neurovascular bundle. Conclusions: This research demonstrated a procedure to verify and standardize the distinct neuroanatomical structures of acupuncture points. Standardization of neuroanatomical targets of acupuncture points will enable researchers and clinicians to obtain reproducible results in clinical treatments and research protocols.