A protein or polypeptide, which comprises two identical Nanobodies, wherein said nanobody is directed against Von Willebrand Factor (vWF), and said nanobody consists of 4 framework regions (FR1 to FR4 respectively) and 3 complementarity determining regions (CDR1 to CDR3 respectively), in which: i) CDR1 essentially consists of: - the amino acid sequence YNPMG [SEQ 10 NO: 22]； or - an amino acid sequence that has 2 or 1 amino acid difference(s) with the amino acid sequence YNPMG [SEQ 10 NO: 22]； and in which: ii) CDR2 essentially consists of an amino acid sequence chosen from the group consisting of: - the amino acid sequence AISRTGGSTYYPDSVEG [SEQ 10 NO: 32]； - an amino acid sequence that has at least 80% sequence identity with the amino acid sequence AISRTGGSTYVPDSVEG [SEQ 10 NO: 32]； and - an amino acid sequence that has 2 or 1 amino acid difference(s) with the amino acid sequence AISRTGGSTYVPDSVEG [SEQ 10 NO: 32]； and in which: iii) CDR3 essentially consists of an amino acid sequence chosen from the group consisting of: - the amino acid sequence AGVRAEDGRVRTLPSEYTF [SEQ 10 NO: 42]； - an amino acid sequence that has at least 80% sequence identity with the amino acid sequence AGVRAEDGRVRTLPSEYTF [SEQ 10 NO: 42]； and - an amino acid sequence that has 1 amino acid difference with the amino acid sequence AGVRAEDGRVRTLPSEYTF [SEQ 10 NO: 42]. Also disclosed are pharmaceutical compositions comprising the above polypeptides and the use of the polypeptide in the treatment of disorders related to platelet-mediated aggregation.Mevcut buluş, von Willebrand Faktörü'ne (vWF) karşı iyileştirilmiş Nanobodies zamanda bu tarz Nano-antikorların birini veya birden fazlasını içeren veya esas olarak bunlardan oluşan polipeptitler ile ilgilidir. Buluş ayrıca, bu tarz Nano-antikorları ve polipeptitleri kodlayan nükleik asitler ile； bu tarz Nano-antikorları ve polipeptitleri hazırlamak için yöntemler ile； bu tarz Nano-antikorları veya polipeptitleri eksprese eden veya eksprese edebilen ko
