Disclosed are hydrogel compositions formed by the mixture of a tetramethylmethane substituted with one or more polyethylene glycols, and wherein each polyethylene glycol substituent is independently further substituted with one or more electrophilic groups, and a tetramethylmethane substituted with one or more polyethylene glycols, and wherein each polyethylene glycol substituent is independently further substituted with one or more nucleophilic groups. Disclosed are also methods of preparing the above hydrogels. The hydrogel compositions can further comprise pharmaceuticals, such as analgesics or local anesthetics. Disclosed are also methods of sealing a wound, preventing post-surgical adhesion, and reducing post-surgical pain using the disclosed hydrogels.